procedure to write case study

In terms of the interview structure, I recommend categorizing the questions in a way that the answers flow into six specific sections that will mirror a successful case study format. Combined, they'll allow you to gather enough information to put together a rich, comprehensive study.

Open with the customer's business.

The goal of this section is to generate a better understanding of the company's current challenges and goals, plus how they fit into the landscape of their industry. Sample questions might include:

• How long have you been in business?
• How many employees do you have?
• What are some of the objectives of your department at this time?

Cite a problem or pain point.

To tell a compelling story, you need context that helps match the customer's needs with your solution. Sample questions might include:

• What challenges and objectives led you to look for a solution?
• What might have happened if you did not identify a solution?
• Did you explore other solutions before this that did not work out? If so, what happened?

Discuss the decision process.

Exploring how the customer decided to work with you helps to guide potential customers through their own decision-making processes.

Sample questions might include:

• How did you hear about our product or service?
• Who was involved in the selection process?
• What was most important to you when evaluating your options?

Explain how a solution was implemented.

The focus here should be placed on the customer's experience during the onboarding process. Sample questions might include:

• How long did it take to get up and running?
• Did that meet your expectations?
• Who was involved in the process?

Explain how the solution works.

The goal of this section is to better understand how the customer is using your product or service. Sample questions might include:

• Is there a particular aspect of the product or service that you rely on most?
• Who is using the product or service?

End with the results.

In this section, you want to uncover impressive measurable outcomes — the more numbers, the better. Sample questions might include:

• How is the product or service helping you save time and increase productivity?
• In what ways does that enhance your competitive advantage?
• How much have you increased metrics X, Y, and Z?

It’s a smart idea to send a copy of your interview questions to your subject ahead of time so they can prepare strong answers and collect the numerical data you need from them.

10. Lay out your case study format.

When it comes time to take all of the information you‘ve collected and actually turn it into something useful, it’s easy to feel overwhelmed. I always do, but I also know that it works out in the end, so I just jump on in and work it through.

So where should you start? What should you include? What's the best way to structure it?

It‘s important to first understand that there is no one-size-fits-all when it comes to the ways you can present a case study.

They can be very visual, which you’ll see in some of the examples we've included below, and can sometimes be communicated through video or photos with a bit of accompanying text.

Here are the sections I’d suggest, and I'll cover these in more detail after #11 below:

• Title. Keep it short. Develop a succinct but interesting project name you can give the work you did with your subject.
• Subtitle. Use this copy to briefly elaborate on the accomplishment. What was done? The case study itself will explain how you got there.
• Executive Summary . A 2-4 sentence summary of the entire story. You'll want to follow it with 2-3 bullet points that display metrics showcasing success.
• About the Subject. An introduction to the person or company you served, which can be pulled from a LinkedIn Business profile or client website.
• Challenges and Objectives. A 2-3 paragraph description of the customer's challenges, before using your product or service. This section should also include the goals or objectives the customer set out to achieve.
• How Product/Service Helped. A 2-3 paragraph section that describes how your product or service provided a solution to their problem.
• Results. A 2-3 paragraph testimonial that proves how your product or service specifically benefited the person or company and helped achieve its goals. Include numbers to quantify your contributions.
• Supporting Visuals or Quotes. Pick one or two powerful quotes that you would feature at the bottom of the sections above, as well as a visual that supports the story you are telling.
• Future Plans. Everyone likes an epilogue. Comment on what's ahead for your case study subject, whether or not those plans involve you.
• Call-to-Action (CTA). Not every case study needs a CTA, but putting a passive one at the end of your case study can encourage your readers to take an action on your website after learning about the work you've done.

When laying out your case study, focus on conveying the information you've gathered in the most clear and concise way possible.

Make it easy to scan and comprehend, and be sure to provide an attractive call-to-action at the bottom — that should provide readers an opportunity to learn more about your product or service.

11. Publish and promote your case study.

Once you‘ve completed your case study, it’s time to publish and promote it.

Some case study formats have pretty obvious promotional outlets — a video case study can go on YouTube, just as an infographic case study can go on Pinterest.

But there are still other ways to publish and promote your case study. Here are a couple of ideas.

Lead Gen in a Blog Post

As stated earlier, written case studies make terrific lead-generators if you convert them into a downloadable format, like a PDF.

To generate leads from your case study, consider writing a blog post that tells an abbreviated story of your client‘s success and asking readers to fill out a form with their name and email address if they’d like to read the rest in your PDF.

Then, promote this blog post on social media, through a Facebook post or a tweet.

Published as a Page on Your Website

As a growing business, you might need to display your case study out in the open to gain the trust of your target audience.

Rather than gating it behind a landing page, publish your case study to its own page on your website, and direct people to it from your homepage with a “Case Studies” or “Testimonials” button along your homepage's top navigation bar.

The traditional case study format includes the following parts: a title and subtitle, a client profile, a summary of the customer’s challenges and objectives, an account of how your solution helped, and a description of the results. You might also want to include supporting visuals and quotes, future plans, and calls-to-action.

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Methodology

• What Is a Case Study? | Definition, Examples & Methods

What Is a Case Study? | Definition, Examples & Methods

Published on May 8, 2019 by Shona McCombes . Revised on November 20, 2023.

A case study is a detailed study of a specific subject, such as a person, group, place, event, organization, or phenomenon. Case studies are commonly used in social, educational, clinical, and business research.

A case study research design usually involves qualitative methods , but quantitative methods are sometimes also used. Case studies are good for describing , comparing, evaluating and understanding different aspects of a research problem .

Table of contents

When to do a case study, step 1: select a case, step 2: build a theoretical framework, step 3: collect your data, step 4: describe and analyze the case, other interesting articles.

A case study is an appropriate research design when you want to gain concrete, contextual, in-depth knowledge about a specific real-world subject. It allows you to explore the key characteristics, meanings, and implications of the case.

Case studies are often a good choice in a thesis or dissertation . They keep your project focused and manageable when you don’t have the time or resources to do large-scale research.

You might use just one complex case study where you explore a single subject in depth, or conduct multiple case studies to compare and illuminate different aspects of your research problem.

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Once you have developed your problem statement and research questions , you should be ready to choose the specific case that you want to focus on. A good case study should have the potential to:

• Provide new or unexpected insights into the subject
• Challenge or complicate existing assumptions and theories
• Propose practical courses of action to resolve a problem
• Open up new directions for future research

TipIf your research is more practical in nature and aims to simultaneously investigate an issue as you solve it, consider conducting action research instead.

Unlike quantitative or experimental research , a strong case study does not require a random or representative sample. In fact, case studies often deliberately focus on unusual, neglected, or outlying cases which may shed new light on the research problem.

Example of an outlying case studyIn the 1960s the town of Roseto, Pennsylvania was discovered to have extremely low rates of heart disease compared to the US average. It became an important case study for understanding previously neglected causes of heart disease.

However, you can also choose a more common or representative case to exemplify a particular category, experience or phenomenon.

Example of a representative case studyIn the 1920s, two sociologists used Muncie, Indiana as a case study of a typical American city that supposedly exemplified the changing culture of the US at the time.

While case studies focus more on concrete details than general theories, they should usually have some connection with theory in the field. This way the case study is not just an isolated description, but is integrated into existing knowledge about the topic. It might aim to:

• Exemplify a theory by showing how it explains the case under investigation
• Expand on a theory by uncovering new concepts and ideas that need to be incorporated
• Challenge a theory by exploring an outlier case that doesn’t fit with established assumptions

To ensure that your analysis of the case has a solid academic grounding, you should conduct a literature review of sources related to the topic and develop a theoretical framework . This means identifying key concepts and theories to guide your analysis and interpretation.

There are many different research methods you can use to collect data on your subject. Case studies tend to focus on qualitative data using methods such as interviews , observations , and analysis of primary and secondary sources (e.g., newspaper articles, photographs, official records). Sometimes a case study will also collect quantitative data.

Example of a mixed methods case studyFor a case study of a wind farm development in a rural area, you could collect quantitative data on employment rates and business revenue, collect qualitative data on local people’s perceptions and experiences, and analyze local and national media coverage of the development.

The aim is to gain as thorough an understanding as possible of the case and its context.

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In writing up the case study, you need to bring together all the relevant aspects to give as complete a picture as possible of the subject.

How you report your findings depends on the type of research you are doing. Some case studies are structured like a standard scientific paper or thesis , with separate sections or chapters for the methods , results and discussion .

Others are written in a more narrative style, aiming to explore the case from various angles and analyze its meanings and implications (for example, by using textual analysis or discourse analysis ).

In all cases, though, make sure to give contextual details about the case, connect it back to the literature and theory, and discuss how it fits into wider patterns or debates.

If you want to know more about statistics , methodology , or research bias , make sure to check out some of our other articles with explanations and examples.

• Normal distribution
• Degrees of freedom
• Null hypothesis
• Discourse analysis
• Control groups
• Mixed methods research
• Non-probability sampling
• Quantitative research
• Ecological validity

Research bias

• Rosenthal effect
• Implicit bias
• Cognitive bias
• Selection bias
• Negativity bias
• Status quo bias

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How to Write a Case Study (Examples & Best Practices)

Sudarshan Somanathan

Head of Content

July 19, 2024

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Promising your clients powerful solutions is great, but what wins them over is cold, hard proof that you’re successful at what you claim.

And that proof is a case study. Crafting one that grabs attention and showcases business expertise isn’t just about laying out the facts and figures—it’s about making your success stories come alive. 

Whether you’re seasoned or just starting, let’s look at actionable tips to write compelling case studies. From integrating best practices and examples to using tools and templates that simplify the process, learn to write case studies that will win clients over! 🙌

Understanding Case Studies

1. identify the case, 2. research, 3. define the problem, 4. develop a hypothesis, 5. plan the structure, step 1: write an impactful introduction, step 2: provide context, step 3: show your research, step 4: present the solution, step 5: reveal the result, step 6: structure and polish, beyond the steps: different methodologies, leverage clickup for writing compelling case studies , narrative case studies , descriptive case studies , exploratory case studies , explanatory case studies , case study templates, case study examples, best practices for writing case studies, landing pages and onboarding , the role and benefit of case studies in various fields, tell powerful business stories with case studies.

A case study is an in-depth analysis of a real-life situation designed to showcase a concept or principle. It’s an impactful tool in problem-solving and decision-making that gives a detailed illustration of a particular issue and its solution within a real-world context. 

Case studies uncover problems, propose solutions, and highlight successes, making them invaluable for businesses, educators, researchers, and professionals across various fields such as medicine and law. 

Case studies help us explore complex issues through detailed contextual analysis. They help understand cause and effect, identify patterns, and develop strategies for future scenarios. 

By studying how others overcame challenges, you can identify best practices and find new, effective approaches to solve problems that are specific to you.

For instance, a business might use a case study to understand how a specific marketing strategy led to increased sales, or a medical professional might examine a case study to understand the progression of a disease and the effectiveness of different treatments. This enables you to make informed decisions in similar future cases instead of decisions based purely on anecdotal theory or just raw data with no context. 

Attaching a case study of your customer’s success to your proposals or response to Request for Proposal ( RFP) documents can lend credibility to your business’ capabilities and enhance your chances of winning over prospective customers.

How to Prepare for a Case Study

Preparation is key to crafting a compelling case study. Follow these steps to ensure you cover all bases:

Pick a relevant, unique subject that addresses a key customer pain point and provides valuable insights. The chosen case should provide a meaningful story and outcome.

Suppose you consider a local environmental group struggling to raise funds for a critical habitat restoration project. This could be a great case study to showcase how you, as a consultant, helped them develop a compelling fundraising strategy, identify new donor segments, and ultimately reach their financial goals.

Gather information and raw data relevant to your topic, including quantitative data (such as statistics and numerical data) and qualitative insights (such as interviews and observations).  

For interviews, you might need to prepare a list of interviewees and research questions beforehand. Comprehensive research helps build a solid foundation for your case study. This is where research plan templates can come in handy. You can use them to structure your research process—from defining the key elements of your case study upfront to formulating clear research questions and outlining the methods you’ll use to gather data.

Let’s go back to our environment group example. To understand the environmental group’s fundraising struggles, you would gather data on their past fundraising campaigns, donor demographics, and website traffic. You would also interview key staff members and conduct focus groups with potential donors to understand their giving habits and concerns.

Clearly outline the issue or challenge faced. A well-defined problem sets the stage for a focused and effective analysis. Spend some time fine-tuning your case study.

In our example, based on your research, you define the problem as the environmental group’s reliance on traditional fundraising methods that were no longer reaching new donors, leading to stagnant funding for critical projects.

Formulate a potential solution or theory to address the problem. Crafted carefully in one or two sentences, this thesis statement will guide your investigation and analysis.

To help the group, your hypothesis could be that by implementing a multi-channel fundraising strategy that leverages social media, targeted email campaigns, and grant proposals, the environmental group can expand its donor base, increase donation amounts, and secure funding for the habitat restoration project.

Decide on the format and structure of your case study. A well-organized structure ensures that your case study is easy to follow and understand. Most case studies follow a chronological structure. This is great for storytelling and helps you take the reader on a journey from the initial challenge to the successful resolution achieved. It allows you to build suspense and highlight the transformation that took place.

For the example given above, you can decide to structure your case study with sections on the environmental group’s mission and the importance of the restoration project, the fundraising challenges they faced, the implemented solutions using your consulting framework, the results achieved (increased donations and project funding), and the key takeaways for other non-profit organizations.

Once you’ve addressed these steps related to case study planning, you’re ready to jump to the writing process. Let’s do that together, one step at a time! 🤝

How to Write a Case Study

Writing a compelling case study goes beyond simply recounting a project’s success. It’s about weaving a narrative that showcases the problem, your approach, and the impactful results. 

Let’s examine how to write case studies that inform and inspire potential customers and stakeholders.

The introduction is prime real estate in your case study—your chance to grab the reader’s attention. 

Here are two effective strategies to start strong

• Intrigue with a challenge: Open with a relatable scenario highlighting the common pain points your solution addresses. Example: “A struggling e-commerce store has stagnant sales despite offering high-quality products. This was the reality for [Company Name] back in [year/month]”
• Spark curiosity with a statistic: Hook your audience with a surprising or thought-provoking statistic related to the industry or challenge. Example: “Did you know that 70% of online shoppers abandon their carts before checkout? [Client Name] faced this very issue, leading to [amount] in lost revenue”

Once you’ve piqued their interest, provide context for your case study:

• Introduce the client: Briefly introduce the client, their industry, and their specific goals or challenges
• Highlight the problem: Clearly define the problem the client faced. Be specific about the impact it had on their business

Give your readers insights into tangible data and evidence of your study:

Quantitative research 

Numbers add credibility to your case study. Gather data relevant to the problem, such as sales figures, website traffic, or customer churn rates.

Qualitative research

Go beyond the numbers! Interview key stakeholders to understand the client’s perspective, thought processes, and emotional impact of the problem.

Behavioral science 

Understanding human behavior can strengthen your case study. Consider incorporating principles of psychology or decision-making to explain why the client’s previous approach wasn’t working and how your solution addressed those behavioral patterns.

For instance, if your case study focuses on improving a website’s conversion rate, you could mention how applying the “scarcity principle” by highlighting limited-time offers or low stock availability can incentivize purchase decisions.

Help your readers understand how exactly you solved the problem:

• Explain your approach: Detail the steps you took to address the client’s problem. Be clear about the specific strategies or methodologies you implemented
• Highlight expertise: Showcase your unique knowledge and expertise. If you developed a custom framework or used innovative techniques, explain them here

The result of your case study shows your success. Ensure you make it appealing to your readers:

• Showcase results with data: Present the positive outcomes achieved through your solution. Quantify the results whenever possible using the data you gathered earlier. For example, if you helped a client increase website traffic, mention the specific percentage increase observed
• Include client testimonials: Weave in positive quotes or testimonials from the client expressing their satisfaction with the results

Now that you know what exactly to put in your case study, you must understand how to present it:

• Organize for clarity: Structure your case study logically. Common sections include Introduction, Client Background, The Challenge, The Solution, Results, and Conclusion
• Pay attention to readability: Use clear and concise language. Break down complex concepts into digestible terms for a wider audience
• Proofread with precision: Ensure your case study is free of grammatical errors and typos. A polished presentation reflects professionalism

While the above steps provide a general framework, case studies can be structured using various methodologies. Here are two common approaches:

• Challenge-Solution-Benefit: This linear structure directly addresses the problem, presents the solution, and highlights the resulting benefits for the client
• Customer journey: This method focuses on the customer’s experience throughout the process. It showcases how your solution helped them navigate challenges and achieve success at each stage of their journey

The chosen methodology depends on the case study’s specific goals and the message you want to convey.

By following these steps and considering different approaches, you can craft compelling case studies that not only inform but also inspire your target audience. 

Remember, a well-written case study is a powerful marketing tool demonstrating your expertise and the value you deliver to clients.

ClickUp is an all-in-one productivity tool. Its intuitive interface and powerful features make it easy to conduct further research, collaborate with team members, and produce high-quality case studies. 

Its marquee feature, ClickUp Brain , is great for writing, editing, and summarizing case studies. This AI-powered tool simplifies the entire process, making it faster and more efficient. 

With ClickUp Brain, you can generate comprehensive case studies from scratch, thanks to its intuitive prompts and suggestions that guide you through each section, ensuring you cover all essential points. Just give it a few bullet points of instruction, and it will help you outline the case study, gather and organize your data, and create a compelling narrative highlighting your achievements and solutions.

Editing is a breeze with ClickUp Brain. The AI can review your content, providing insights and suggestions for improvement. It checks for clarity, coherence, and grammatical accuracy, ensuring your case study reads well and conveys your message effectively. This saves you time and effort, allowing you to focus on fine-tuning your content rather than doing the heavy lifting!

When it comes to summarizing, ClickUp Brain excels by distilling lengthy case studies with too much detail into concise, impactful summaries. This is particularly useful for creating an executive summary of your case study that won’t overwhelm your audience with too much information at once while still sharing the key details with them. 

By leveraging ClickUp Brain, you can produce polished, professional case studies that effectively communicate your successes and expertise.

Case Study Formats

Case studies have various formats, depending on their purpose and audience. This also determines their length. Marketing case studies are usually 500–700 words long. 

In-depth ones for academic, financial, or scientific purposes can exceed 1,000 words, including detailed data, analysis, methodologies, and interviews. Here are some common case study formats with examples:

They tell the story of the case in a linear format . This narrative form is ideal for engaging readers and making complex information more accessible. For instance, a narrative case study about a startup’s journey from inception to success will captivate readers by walking them through each milestone, highlighting challenges and triumphs. A customer success story can be another example.

This format provides a detailed description of the case and its context . It’s useful for presenting a comprehensive overview of a particular situation. An example would be a case study on a company’s operational processes describing how a specific change in workflow improved efficiency, with detailed descriptions of each step and the overall impact on productivity.

Investigates a phenomenon in a preliminary way to lay the groundwork for future studies . This format is often used in academic research to explore new areas of interest. For example, an exploratory case study might examine the initial effects of remote work on employee productivity during the early months of the COVID-19 pandemic, setting the stage for more extensive research.

This format is ideal for understanding the cause-and-effect relationships in complex scenarios. A case study explaining how a particular marketing strategy led to a significant increase in sales can provide insights into the specific tactics used, customer responses, and overall outcomes, helping clarify the strategy’s direct impact on sales performance.

Each format serves a distinct purpose and can be tailored to the specific needs of your audience and the goals of your case study.

Having templates to structure your case study will save you a great deal of time. 

They help streamline your case study creation process and ensure consistency in formatting. They also provide a framework for organizing your information and presenting it well.

Try the ClickUp Case Study Template to get a head start on your case studies. It helps capture critical information such as project background, challenges faced, strategies implemented, and measurable outcomes. 

This template includes prompts and sections that cover all necessary aspects of a case study, from initial analysis to final results. Its intuitive format helps streamline the writing process, making it easier to organize data and insights coherently, eventually allowing you to showcase the tangible benefits of your work.

If you’re looking to craft visually appealing and well-structured case studies, the ClickUp Case Study Design Template is what you need. This template provides a comprehensive layout that guides you through the essential components of a case study, such as problem statements, solutions, methodologies, and results.

With its pre-designed sections, you can easily organize your content, ensuring that each part of your case study is clearly defined and logically presented. The template’s customizable elements allow you to tailor the design to match your brand’s aesthetics , making your case study informative, engaging, and professional-looking. 

By using this template, you can save time on formatting and focus more on the important stuff.

Case studies illustrate how solutions are applied in various scenarios, offering valuable insights and practical lessons. Here are some other real-world examples:

Business case study: This type of case study analyzes a company’s strategy and outcomes. For example, this is a ClickUp case study featuring Cartoon Network that doubled its output in 50% less time. It outlines systematic ways the business cut short on duplicative efforts, facilitated deeper real-time collaboration, and leveraged insights to boost its productivity.

Medical case study: It examines a patient’s history and treatment. This National Institutes of Health example details a patient’s symptoms, diagnosis, treatment, and recovery, providing a comprehensive view of the medical journey. It offers medical practitioners valuable insights into diagnosing and managing similar cases.

Technology implementation case study: This details how an organization implemented new technology. For example, a Microsoft case study explores how a company adopted Microsoft Azure to enhance its cloud computing capabilities. It covers the challenges faced, the implementation process, and the positive impact on business operations.

Marketing case study: This form of case study analyzes a marketing campaign’s strategy and results. For instance, Comedy Central launched an innovative search campaign using YouTube videos to introduce Trevor Noah as the new host of “The Daily Show” and engage fans through an interactive Easter egg hunt. The campaign generated 38M impressions and 2.8M views with high engagement rates.

We’ve curated a set of business best practices for writing and promoting impactful case studies to help you create them. 

Incorporate key elements

• Start with a strong introduction: Grab the reader’s attention and set the stage for your analysis. A compelling introduction can draw readers in and make them want to learn more about your case study. This introduction draws on a historical timeline and sets a very strong narrative

• Be clear and concise: Keep your writing concise and focused. Avoid unnecessary jargon and complex language that might confuse readers
• Use visuals: Enhance your case study with charts, graphs, and images to illustrate important sections. Visuals can help make complex information more accessible and engaging

• Include real data: Support your analysis with real data and statistics. Providing concrete evidence can strengthen your arguments and add credibility to your case study

• Tell a story: Make your case study engaging by telling a compelling customer story. Use narrative techniques to bring your case study to life and make it more relatable to readers

Promoting case studies 

Your case study must be supported by a structured  marketing plan . To reach a wider audience, leverage social media marketing and content distribution. Share your case studies on LinkedIn, Twitter, and industry-specific forums to generate interest and engagement.

You can repurpose key elements of the case study into bite-sized LinkedIn posts or Tweets. You can even capture client video testimonials to support the results highlighted in the case studies and share them on platforms like Instagram and TikTok. Additionally, consider using SEO best practices to ensure your case studies are easily discoverable online.

Presenting a Case Study

Presenting a case study effectively is crucial for conveying your findings and recommendations. Follow these steps:

• Prepare a clear outline: Organize your presentation logically with a clear outline. This helps ensure that your presentation is easy to follow and that you cover all key points
• Use visual aids: Enhance your presentation with slides, charts, and graphs. Visual aids can help make your presentation more engaging and easier to understand
• Engage your audience: Encourage questions and discussions to engage your audience. Interaction can help reinforce your message and make your presentation more memorable
• Highlight key points: Emphasize the most important findings and recommendations. Make sure your audience leaves with a clear understanding of the main takeaways from your case study

Create dedicated landing pages to showcase your case studies. Use effective onboarding techniques to guide readers through your content. 

For example, you can create a landing page on your website with a strong headline, an overview of your case study, key findings, and a call to action encouraging readers to download the full report. 

Here’s an example from the National Library of Medicine

Another best practice most businesses follow is a landing page featuring the full collection of their case studies . This helps your target audience quickly review all the powerful business stories you have on offer and select the one that’s most relevant to them. 

Take a look at ClickUp’s landing page for case studies below.

Case studies are used across various fields to provide in-depth analysis of relevant theories and insights.

Nursing  

Case studies in nursing help understand patient care and treatment outcomes. 

For example, a case study detailing a diabetic patient’s journey can highlight effective management strategies and complications, such as monitoring blood sugar levels, dietary adjustments, and medication adherence. 

This comprehensive account can offer valuable lessons for healthcare providers, contributing to better patient care practices and education.

Public policy

Public policy case studies provide a detailed analysis of policy decisions and their impact. 

For instance, a case study on a city’s implementation of a new public transportation system can showcase successful interventions, such as increased ridership and reduced traffic congestion. It can also identify areas for improvement, such as the need for better infrastructure or more frequent service. 

These insights can guide future policy decisions, helping policymakers design more effective and efficient public services.

Business case study examples in marketing illustrate successful campaigns and strategies. 

For instance, a case study on Apple’s marketing strategy for the iPhone highlights how they arrived at their creative briefs , positioning, branding, and targeted advertising to capture a significant market share. 

This detailed account of Apple’s approach to market research, consumer behavior analysis, and creative advertising techniques can offer valuable lessons for other businesses looking to enhance their marketing efforts and connect more effectively with their target audience.

Operations management

These case studies provide insights into process improvements and operational efficiency. 

For example, this case study on Toyota’s implementation of lean manufacturing principles shows how the company reduced waste, improved production efficiency, and increased overall product quality. 

By examining the specific steps Toyota took to streamline its operations, such as adopting just-in-time inventory systems and continuous improvement practices, other businesses can learn how to optimize their processes and achieve higher productivity.

Strategic planning

Case studies in strategic planning demonstrate how companies navigate complex business environments. 

For example, a case study on Netflix’s transition from a DVD rental service to a global streaming giant reveals the strategic decisions that fueled its growth. This includes their investment in original content, adoption of new technologies, and expansion into international markets. 

By understanding the strategic choices and challenges Netflix faces, other businesses can gain insights into how to adapt their strategies to changing market conditions and emerging opportunities.

These examples illustrate how case studies in various fields provide actionable insights and practical knowledge to help companies innovate, improve efficiency, and make informed strategic decisions.

Writing an effective case study is more than just presenting data; it’s about telling a story that resonates with your audience and showcases the impact of your solutions. 

By focusing on clear objectives, customer quotes, thorough research, and engaging narratives, you can create strong case studies that not only highlight your successes with previous customers but also build trust with prospective clients and future customers. Remember, a well-crafted case study can help you achieve your marketing goals .

One tool that can significantly streamline the process of creating impactful case studies is ClickUp. With its robust project management features, ClickUp helps you organize your case study research, track progress, and collaborate seamlessly with your team. 

Its AI-powered features streamline the writing process , allowing you to focus on in-depth analysis and creativity. 

Use ClickUp’s templates to structure your case study, set deadlines, and capture every detail accurately. Its document and task management capabilities ensure that your case study is well-organized, visually appealing, and professional. Don’t take our word for it. Try it yourself. 

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How to Write a Case Study: A Complete Guide with Templates

Writing compelling and insightful case studies is a marketer’s biggest job, yet most get frustrated with this content. The challenge? Figuring out how to write a case study that not only highlights the company’s strongest suit but engages new clients with strategic information. If you often struggle with making case studies as more than just dry facts and figures, you’re leading your efforts to missed opportunities.

How to Write a Case Study Step-by-Step 

• Craft a Compelling Headline: Highlight the main success with a clear, direct title.
• Start with a Strong Introduction: Provide a broad overview and hook the reader.
• Discuss Unique Client Challenges: Highlight specific industry-related challenges.
• Highlight the Solution: Showcase your strategies and key results.
• Present Quantifiable Results: Use data and visuals to demonstrate impact.
• Be Clear and Concise: Stick to the point and support claims with data.
• Treat Your Case Study Like a Story: Focus on the customer’s journey and success.
• Use Direct Quotes from the Client: Add authenticity with client testimonials.
• Make the Key Takeaway Clear: Reinforce your expertise and the solution’s value.
• Include a Call to Action (CTA): Guide the reader on what to do next.
• Make It Readable: Use simple language, short paragraphs, and bullet points.
• Finalize and Proofread: Review for errors and ensure a smooth flow.

In this blog, you’ll discover a step-by-step guide that simplifies the process, making it easier to create interesting case studies. From planning to writing, I’ve got you covered. So, let’s start with some basics. 

Table of Contents

What is the format of a case study.

• How to Plan a Case Study 

How to Write a Case Study

How to summarize a case study, how to cite a case study.

A well-structured case study isn’t just a collection of facts—it’s a powerful marketing tool that tells a compelling story. Using the right format for a case study ensures that your message is clear, engaging, and impactful. 

The proper format guides readers through the narrative with hierarchy and scannability, helping them connect with your brand on a deeper level. Most importantly, it empowers you as a marketer to set clear goals for presenting your case studies and ensures you deliver the correct information effectively!

Case studies format helps you to plan and write the case study for your clients. With this outline in mind, you can create steps to complete the process of writing and publishing your case study research. There are eight components of a case study that are essential for building a layout of information in the correct order that makes sense to the viewers. 

Start with a catchy “Title” that grabs attention and an “Overview” that sets the stage. Clearly define the “Problem” your client faced, and then showcase your “Solution” in detail. Highlight the success with “Results” that are measurable and impactful. Add authenticity with “Testimonials and Quotes” from satisfied clients. Wrap it up with a firm “Conclusion” and a compelling “Call to Action” in the “About Us” section that guides the reader on what to do next. 

By following this format, you create a case study design that resonates with your audience and effectively showcases your brand’s value.

Check out the marketing case study template I’ve included below—it has a clear outline that makes it easy to see how sticking to a format can help you plan and write the entire thing.

How to Plan a Case Study 

Now comes the big part! Understanding what to include in a case study outline is just the starting point for beginners. The real challenge lies in creating a step-by-step plan to craft that outline and filling it in with the right information!

1. Set Clear Goals for Your Case Study

Before diving into how to write a case study, defining your ultimate objective is essential. Think about it—what do you want your audience to take away from this case study? For example, your goal is to showcase how your SEO strategies boosted a client’s organic traffic by 150% in just six months. This clear goal will shape your entire narrative and ensure that your case study is laser-focused on demonstrating your expertise and the value you bring.

2. Select a Client that Highlights Your Strongest Suit

Choosing the right client or subject is vital while creating case studies. Imagine you’ve worked with a small e-commerce brand struggling to rank for competitive keywords. Your strategies helped them rank on the first page and increase conversions. This is the perfect client for your case study because their success story directly showcases your SEO prowess. 

By picking a client whose experience aligns with your goals, you’ll create a case study that resonates with your target audience.

3. Reach Out to Your Client for Collaboration

Now that you’ve identified the ideal client, it’s time to reach out. Let’s say you contact your client and explain how a case study can highlight their remarkable success story. It’s a great way to spotlight a mutual collaboration based on credibility. Their buy-in is crucial; their insights and data will authenticate your case study.

4. Gather Comprehensive Data and Insights

Data is the lifeblood of any compelling case study. For instance, in your SEO case study, you’ll need to gather data on key metrics like keyword rankings, organic traffic, and conversion rates before and after implementing your strategies. Let’s say your client saw a 50% increase in organic traffic within three months of optimizing their website. Collecting this data will help you build a robust, evidence-based narrative highlighting your impact.

It’s essential to monitor the before-and-after data to track the effectiveness of implementing your strategies. 

5. Prepare Insightful Questions and Conduct Interviews

It would be best to ask the right questions to get the most out of your client interviews. Imagine asking your client, “What specific challenges were you facing with your organic search rankings before we started working together?” or “How did our SEO strategies help you achieve your business goals?” These questions will lead to detailed responses that add depth to your case study, making it more than just numbers on a page.

Always ask questions that uncover the key challenges your clients face. This way, your prospects will know when to turn to you to navigate or overcome similar obstacles in their business.

Since I’m giving an example of an SEO case study in marketing, you can try these questions to interview your existing client. Obviously, you can modify the sentences according to your industry basics, but these types of questions are fundamental for collecting structured data from your clients. 

• What were your business’s main SEO challenges before we started working together?
• Can you describe your initial expectations for implementing our SEO strategies?
• What specific SEO tactics did we implement that you found most effective?
• How did you monitor and measure the impact of these strategies on your organic traffic?
• What were the key metrics or results that stood out to you after the first three months?

6. Ask Questions That Drive the Story Forward

Impactful questions are the backbone of a strong case study. They allow you to highlight the unique value you delivered to your clients. You can effortlessly showcase your USPs within the case study by asking the right questions. 

Focus on inquiring about the effectiveness of your services and strategies, their impact, and which aspects of the solution were most beneficial. This insight will be your key to demonstrating the tangible benefits you offer your clients. 

Consider asking questions like:

• Can you share a moment when you first noticed a significant improvement in your website’s organic traffic?
• How did the increase in organic traffic impact other business areas, such as lead generation or sales?
• What feedback did your team or customers receive regarding the changes in your site’s performance?
• Looking back, what do you believe was the most critical factor in achieving these results?
• How has this success with SEO influenced your overall marketing strategy moving forward?

These types of questions encourage clients to share their experiences in a way that paints a vivid picture for your readers, making the case study more relatable and engaging.

7. Draft a Clear and Organized Outline

With all the data and insights gathered, it’s time to create a well-structured case study outline. Let’s say you start with a brief overview of your client’s business and its challenges, followed by a detailed account of the SEO strategies you implemented. Then, you showcase the results with hard data and close with client testimonials and a solid call to action. 

As mentioned above, organizing your content in a logical, easy-to-follow format will help you write a case study that not only informs but also captivates your audience.

These steps are the cornerstones of designing a case study. Once you complete this checklist, you can proceed to the next step, which is writing a case study. Since I discussed planning an SEO case study extensively, here is a case study template that perfectly illustrates the process. 

You want to create an informative case study for your prospects. But how do you make sure it’s done right? Here’s a step-by-step guide on how to write a case study that drives results.

1. Craft a Compelling Headline  

Your headline is the first thing readers see, so make it count! It should grab attention and hint at the success story you’re about to share.

How to Write a Case Study Title:

1. Highlight the Result: Showcase the critical success, like “Increased Sales by 200%.”

2. Be Clear and Direct: Make sure the headline is straightforward to grasp.

3. Use Action Words: Start with strong verbs like “How We” or “Achieved.”

4. Mention Client or Industry: Include relevant details for specificity.

5. Keep It Short: Make it concise and attention-grabbing.

2. Start with a Strong Introduction  

Kick off your case study with a broad overview that sets the stage. Provide the big picture and construct a clear narrative that draws readers in, making them eager to learn more about how you solved a significant challenge.

Look at the consulting case study template , which includes a stunning overview description and precise instructions for writing a short and compelling introduction. You can add every little detail to hook the reader.

Get This Template and More

3. Discuss Specific Challenges of Your Client

This is where your prospect can truly connect. By highlighting unique yet specific challenges to their industry, you give them insight into issues they might not have encountered yet—or ones they’ve already faced. This way, they’ll know exactly who to turn to when similar challenges arise.

The following financial case study template provides a brief flow of the company’s common challenges in the financial analysis process. The template is almost ready to use with this domain-specific content, requiring minimal adjustments to design your case study.

4. Highlight the Solution  

Now, dive into the heart of the story. Highlight the solution you provided, and make sure to include a notable achievement or key result. This is your chance to shine!

Check out the format for presenting the implications of your service on your client’s business. The benefits should be well-written and data-driven to convince your upcoming clients. This graphic design case study format helps you understand the specific impacts a company seeks from a reputable graphic design firm.

5. Present Quantifiable Results  

When sharing the outcome, numbers speak louder than words. Present quantifiable results that clearly demonstrate the impact of your solution. Use graphs or charts to make the data easy to digest and visually appealing.

6. Be Clear and Concise  

Less is more. Stick to the point and offer just the right amount of detail to keep your readers engaged. Include data that supports your claims, but avoid overwhelming them with too much information.

Here’s a stunning sales consulting case study that uses a simple case study layout and details written in readable, plain language to gauge more utility. 

7. Treat Your Case Study Like a Story  

Focus on your customer’s journey. Think of your case study as a story in which your client is the hero, and your solution is the tool that helped them succeed. This approach will make your case study relatable and compelling.

8. Be as Specific as Possible  

Don’t be vague—details matter. Mention the specific company and its industry to let your audience know that the challenge and solution are relevant to them. The more precise you are, the more credible and trustworthy your case study will be.

Check out the sample case study below for payroll accounting. The details are clearly organized and grouped to emphasize the type of case study.

Also, the next case study template displays very specific problems that a company faces when it lacks digital marketing expertise. 

These templates make it a breeze to craft a case study that’s perfect for your niche.

9. Use Direct Quotes from the Client  

Quotes from your client add authenticity and credibility. They give readers insight into the client’s perspective and make your case study more relatable. Plus, a glowing testimonial is always a nice touch!

The following inbound marketing case study has a prominent client testimonial. With the brief instructions on this template, it’s easier for you to understand how to capture the golden words of your client and use them as a word-of-mouth strategy within the case study. 

10. Pick an Interesting Angle  

Find a unique angle that makes your case study stand out. Maybe it’s an unexpected challenge you overcame, or perhaps it’s a particularly innovative solution. Whatever it is, make it intriguing.

11. Make the Key Takeaway Crystal Clear  

Your readers should walk away with a clear understanding of the main point of your case study. This takeaway should reinforce your expertise and the value of your solution.

12. Include a Call to Action (CTA)  

Don’t leave your readers hanging—tell them what to do next! Include a compelling summary about your company, showcase your happy client base, and conclude the journey with a strong CTA, whether to contact you for a consultation, download a related resource, or learn more about your services on social media, like the following case study template design.

12. Format Professionally  

The design of the case study is just as important as the content. A well-formatted, visually appealing document makes a great impression and enhances readability. With ready-to-use niche-oriented templates, you can easily create a professional-looking case study that impresses and converts. Here is an eye-catching template for an AI assistant software case study that displays a sleek and well-navigated format.

13. Make It Readable  

Easy readability is key. Use simple language, short paragraphs, and bullet points where appropriate. Your case study should be easy to scan and digest. Follow the thirteen design principles to create a standout piece that enhances your marketing efforts.

To understand this, take a look at the following consulting case study template. 

14. Finalize and Proofread Your Case Study  

In order to excel in how to write case studies, give your case study a final review before you hit publish. Proofread carefully to catch any typos or errors, and make sure everything flows smoothly. A polished case study reflects your attention to detail and professionalism.

To effectively summarize a case study, start by completing all sections, including the introduction, challenges, solutions, and results. This approach helps marketers identify key points to highlight, making it easier to craft a succinct and engaging summary. 

One tricky thing is the length of the case study summary. So, how long should a case study summary be? 

The length of a case study summary can vary depending on the details you’re covering. Generally, it should be kept concise, usually spanning a couple of lines or up to a single page with several paragraphs. If you’re crafting a customer case study and want to flex your storytelling muscles, it’s perfectly fine for the summary to stretch to a full page.

If summarizing a case study seems daunting, try DocHipo’s advanced AI Writer tool, which effortlessly creates a crisp and concise summary.

Watch this short video to use it.

This is the last step in writing a case study analysis. Citation in a case study is the practice of giving proper credit to the sources you reference or use in your research. It helps validate your work, shows the depth of your research, and avoids plagiarism. Follow the below steps to cite a case study:

• Identify the Source: Gather details like the author, title, publication year, and where the case study was published.
• Choose a Citation Style: Follow the specific formatting style (APA, MLA, Chicago, etc.) required for your work.
• Format the Citation: Arrange the details according to the chosen citation style.
• Include In-Text Citations: Place citations within the text or paragraphs for the case study.
• Create a References List: At the end of your case study, compile all your sources in a bibliography or reference list.

For case studies, citations in APA and MLA styles are very common. If you are just beginning, then you might be confused about these case study citation formats.

Hence, take a look at the picture below, which easily comprehends the APA vs MLA citation features. 

Still feeling overwhelmed about case studies? Be stress-free with the most convenient case study maker, which saves time and allows you to present data in the most attention-grabbing way. 

Watch the video to create case studies in minutes with DocHipo’s case study maker. 

Conclusion 

To summarize, if you want to write a case study, start with a proper case study format, plan the case study, and finally write it with all the information in hand. Then, write a summary to provide an overview of your case study, and finally, add citations for reference. 

Meanwhile, if you want to design a case study, Try DocHipo templates. Sign up to explore all the case study templates. 

What is the structure of a case study?

A case study typically includes the following sections: Title, Introduction, Background, Problem Statement, Solutions, Results, and Conclusion. Each section serves to tell a comprehensive story of the business, from the issue at hand to the resolution and outcomes.

What are the 5 essential elements of a great case study?

The 5 essential elements are: 1) Clear Objective, 2) Detailed Background, 3) Specific Challenges, 4) Effective Solutions, and 5) Measurable Results. These components provide a compelling narrative that highlights the value delivered.

How to begin a case study?

Start a case study by defining the purpose and scope of the study. Introduce the subject, outline the problem, and provide background information to give readers context. This sets the stage for the detailed analysis that follows.

How to make an introduction in case study?

To craft a compelling introduction, briefly describe the subject, outline the problem they faced, and explain why the study is relevant. This section should grab the reader’s attention and make them interested in the rest of the study.

How to make a business case study?

A business case study should begin with a clear objective and background information. Identify the problem, explain the solutions implemented, and conclude with the results achieved. Use real data and quotes from stakeholders to enhance credibility.

How to write a case study step by step?

To write a case study step by step, start by identifying the case you want to explore and gathering relevant data on the subject. Outline the structure of your case study, then craft an engaging Introduction to set the context. Next, detail the Background and Challenges faced, followed by the Solutions applied. Share the Results and Conclusion to highlight the impact. Finally, edit and proofread your case study to ensure clarity and accuracy.

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What Is a Case Study? How to Write, Examples, and Template

In this post

How to write a case study

Case study template, case study examples, types of case studies, what are the benefits of case studies , what are the limitations of case studies , case study vs. testimonial.

In today's marketplace, conveying your product's value through a compelling narrative is crucial to genuinely connecting with your customers.

Your business can use marketing analytics tools to understand what customers want to know about your product. Once you have this information, the next step is to showcase your product and its benefits to your target audience. This strategy involves a mix of data, analysis, and storytelling. Combining these elements allows you to create a narrative that engages your audience. So, how can you do this effectively?

What is a case study? 

A case study is a powerful tool for showcasing a business's success in helping clients achieve their goals. It's a form of storytelling that details real-world scenarios where a business implemented its solutions to deliver positive results for a client.

In this article, we explore the concept of a case study , including its writing process, benefits, various types, challenges, and more.

Understanding how to write a case study is an invaluable skill. You'll need to embrace decision-making – from deciding which customers to feature to designing the best format to make them as engaging as possible.  This can feel overwhelming in a hurry, so let's break it down.

Step 1: Reach out to the target persona

If you've been in business for a while, you have no shortage of happy customers. But w ith limited time and resources, you can't choose everyone.  So, take some time beforehand to flesh out your target buyer personas. 

Once you know precisely who you're targeting, go through your stable of happy customers to find a buyer representative of the audience you're trying to reach. The closer their problems, goals, and industries align, the more your case study will resonate.

What if you have more than one buyer persona? No problem. This is a common situation for companies because buyers comprise an entire committee. You might be marketing to procurement experts, executives, engineers, etc. Try to develop a case study tailored to each key persona. This might be a long-term goal, and that's fine. The better you can personalize the experience for each stakeholder, the easier it is to keep their attention.  

Here are a few considerations to think about before research:

• Products/services of yours the customer uses (and how familiar they are with them)
• The customer's brand recognition in the industry
• Whether the results they've achieved are specific and remarkable
• Whether they've switched from a competitor's product/service
• How closely aligned they are with your target audience

These items are just a jumping-off point as you develop your criteria.  Once you have a list, run each customer through it to determine your top targets. Approach the ones on the top (your "dream" case study subjects) and work your way down as needed.

Who to interview

You should consider interviewing top-level managers or executives because those are high-profile positions. But consider how close they are to your product and its results.

Focusing on an office manager or engineer who uses your product daily would be better. Look for someone with a courtside view of the effects.

The ways to request customer participation in case studies can vary, but certain principles can improve your chances:

• Make it easy for customers to work with you, respecting their valuable time. Be well-prepared and minimize their involvement.
• Emphasize how customers will benefit through increased publicity, revenue opportunities, or recognition for their success. 
• Acknowledge their contributions and showcase their achievements.
• Standardizing the request process with a script incorporating these principles can help your team consistently secure case study approvals and track performance.

Step 2: Prepare for the interview

Case study interviews are like school exams. The more prepared you are for them, the better they turn out. Preparing thoroughly also shows participants that you value their time. You don't waste precious minutes rehashing things you should have already known. You focus on getting the information you need as efficiently as possible.

You can conduct your case study interview in multiple formats, from exchanging emails to in-person interviews. This isn't a trivial decision.  As you'll see in the chart below, each format has its unique advantages and disadvantages. 

You'll also have to consider who will ask and answer the questions during your case study interview. It's wise to consider this while considering the case study format.  The number of participants factors into which format will work best. Pulling off an in-person interview becomes much harder if you're trying to juggle four or five people's busy schedules. Try a video conference instead.

Before interviewing your case study participant, it is crucial to identify the specific questions that need to be asked.  It's essential to thoroughly evaluate your collaboration with the client and understand how your product's contributions impact the company. 

Remember that structuring your case study is akin to crafting a compelling narrative. To achieve this, follow a structured approach:

• Beginning of your story. Delve into the customer's challenge that ultimately led them to do business with you. What were their problems like? What drove them to make a decision finally? Why did they choose you?
• The middle of the case study.  Your audience also wants to know about the experience of working with you. Your customer has taken action to address their problems. What happened once you got on board?
• An ending that makes you the hero.  Describe the specific results your company produced for the customer. How has the customer's business (and life) changed once they implemented your solution?

Sample questions for the case study interview

If you're preparing for a case study interview, here are some sample case study research questions to help you get started:

• What challenges led you to seek a solution?
• When did you realize the need for immediate action? Was there a tipping point?
• How did you decide on the criteria for choosing a B2B solution, and who was involved?
• What set our product or service apart from others you considered?
• How was your experience working with us post-purchase?
• Were there any pleasant surprises or exceeded expectations during our collaboration?
• How smoothly did your team integrate our solution into their workflows?
• How long before you started seeing positive results?
• How have you benefited from our products or services?
• How do you measure the value our product or service provides?

Step 3: Conduct the interview

Preparing for case study interviews can be different from everyday conversations. Here are some tips to keep in mind:

• Create a comfortable atmosphere.  Before diving into the discussion, talk about their business and personal interests. Ensure everyone is at ease, and address any questions or concerns.
• Prioritize key questions.  Lead with your most crucial questions to respect your customer's time. Interview lengths can vary, so starting with the essentials ensures you get the vital information.
• Be flexible.  Case study interviews don't have to be rigid. If your interviewee goes "off script," embrace it. Their spontaneous responses often provide valuable insights.
• Record the interview.  If not conducted via email, ask for permission to record the interview. This lets you focus on the conversation and capture valuable quotes without distractions.

Step 4: Figure out who will create the case study

When creating written case studies for your business, deciding who should handle the writing depends on cost, perspective, and revisions.

Outsourcing might be pricier, but it ensures a professionally crafted outcome. On the other hand, in-house writing has its considerations, including understanding your customers and products. 

Technical expertise and equipment are needed for video case studies, which often leads companies to consider outsourcing due to production and editing costs. 

Tip: When outsourcing work, it's essential to clearly understand pricing details to avoid surprises and unexpected charges during payment.

Step 5: Utilize storytelling

Understanding and applying storytelling elements can make your case studies unforgettable, offering a competitive edge. 

Source: The Framework Bank

Every great study follows a narrative arc (also called a "story arc"). This arc represents how a character faces challenges, struggles against raising stakes, and encounters a formidable obstacle before the tension resolves.

In a case study narrative, consider:

• Exposition. Provide background information about the company, revealing their "old life" before becoming your customer.
• Inciting incident. Highlight the problem that drove the customer to seek a solution, creating a sense of urgency.
• Obstacles (rising action). Describe the customer's journey in researching and evaluating solutions, building tension as they explore options.
• Midpoint. Explain what made the business choose your product or service and what set you apart.
• Climax. Showcase the success achieved with your product.
• Denouement. Describe the customer's transformed business and end with a call-to-action for the reader to take the next step.

Step 6: Design the case study

The adage "Don't judge a book by its cover" is familiar, but people tend to do just that quite often!

A poor layout can deter readers even if you have an outstanding case study. To create an engaging case study, follow these steps:

• Craft a compelling title. Just like you wouldn't read a newspaper article without an eye-catching headline, the same goes for case studies. Start with a title that grabs attention.
• Organize your content. Break down your content into different sections, such as challenges, results, etc. Each section can also include subsections. This case study approach divides the content into manageable portions, preventing readers from feeling overwhelmed by lengthy blocks of text.
• Conciseness is key. Keep your case study as concise as possible. The most compelling case studies are precisely long enough to introduce the customer's challenge, experience with your solution, and outstanding results. Prioritize clarity and omit any sections that may detract from the main storyline.
• Utilize visual elements. To break up text and maintain reader interest, incorporate visual elements like callout boxes, bulleted lists, and sidebars.
• Include charts and images. Summarize results and simplify complex topics by including pictures and charts. Visual aids enhance the overall appeal of your case study.
• Embrace white space. Avoid overwhelming walls of text to prevent reader fatigue. Opt for plenty of white space, use shorter paragraphs, and employ subsections to ensure easy readability and navigation.
• Enhance video case studies. In video case studies, elements like music, fonts, and color grading are pivotal in setting the right tone. Choose music that complements your message and use it strategically throughout your story. Carefully select fonts to convey the desired style, and consider how lighting and color grading can influence the mood. These elements collectively help create the desired tone for your video case study.

Step 7: Edits and revisions

Once you've finished the interview and created your case study, the hardest part is over. Now's the time for editing and revision. This might feel frustrating for impatient B2B marketers, but it can turn good stories into great ones.

Ideally, you'll want to submit your case study through two different rounds of editing and revisions:

• Internal review. Seek feedback from various team members to ensure your case study is captivating and error-free. Gather perspectives from marketing, sales, and those in close contact with customers for well-rounded insights. Use patterns from this feedback to guide revisions and apply lessons to future case studies.
• Customer feedback. Share the case study with customers to make them feel valued and ensure accuracy. Let them review quotes and data points, as they are the "heroes" of the story, and their logos will be prominently featured. This step maintains positive customer relationships.

Case study mistakes to avoid

• Ensure easy access to case studies on your website.
• Spotlight the customer, not just your business.
• Tailor each case study to a specific audience.
• Avoid excessive industry jargon in your content.

Step 8: Publishing

Take a moment to proofread your case study one more time carefully. Even if you're reasonably confident you've caught all the errors, it's always a good idea to check. Your case study will be a valuable marketing tool for years, so it's worth the investment to ensure it's flawless. Once done, your case study is all set to go!

Consider sharing a copy of the completed case study with your customer as a thoughtful gesture. They'll likely appreciate it; some may want to keep it for their records. After all, your case study wouldn't have been possible without their help, and they deserve to see the final product.

Where you publish your case study depends on its role in your overall marketing strategy. If you want to reach as many people as possible with your case study, consider publishing it on your website and social media platforms. 

Tip: Some companies prefer to keep their case studies exclusive, making them available only to those who request them. This approach is often taken to control access to valuable information and to engage more deeply with potential customers who express specific interests. It can create a sense of exclusivity and encourage interested parties to engage directly with the company.

Step 9: Case study distribution

When sharing individual case studies, concentrate on reaching the audience with the most influence on purchasing decisions

Here are some common distribution channels to consider:

• Sales teams. Share case studies to enhance customer interactions, retention , and upselling among your sales and customer success teams. Keep them updated on new studies and offer easily accessible formats like PDFs or landing page links.
• Company website. Feature case studies on your website to establish authority and provide valuable information to potential buyers. Organize them by categories such as location, size, industry, challenges, and products or services used for effective presentation.
• Events. Use live events like conferences and webinars to distribute printed case study copies, showcase video case studies at trade show booths, and conclude webinars with links to your case study library. This creative approach blends personal interactions with compelling content.
• Industry journalists. Engage relevant industry journalists to gain media coverage by identifying suitable publications and journalists covering related topics. Building relationships is vital, and platforms like HARO (Help A Reporter Out) can facilitate connections, especially if your competitors have received coverage before.

Want to learn more about Marketing Analytics Software? Explore Marketing Analytics products.

It can seem daunting to transform the information you've gathered into a cohesive narrative.  We’ve created a versatile case study template that can serve as a solid starting point for your case study.

With this template, your business can explore any solutions offered to satisfied customers, covering their background, the factors that led them to choose your services, and their outcomes.

The template boasts a straightforward design, featuring distinct sections that guide you in effectively narrating your and your customer's story. However, remember that limitless ways to showcase your business's accomplishments exist.

To assist you in this process, here's a breakdown of the recommended sections to include in a case study:

• Title.  Keep it concise. Create a brief yet engaging project title summarizing your work with your subject. Consider your title like a newspaper headline; do it well, and readers will want to learn more. 
• Subtitle . Use this section to elaborate on the achievement briefly. Make it creative and catchy to engage your audience.
• Executive summary.  Use this as an overview of the story, followed by 2-3 bullet points highlighting key success metrics.
• Challenges and objectives. This section describes the customer's challenges before adopting your product or service, along with the goals or objectives they sought to achieve.
• How product/service helped.  A paragraph explaining how your product or service addressed their problem.
• Testimonials.  Incorporate short quotes or statements from the individuals involved in the case study, sharing their perspectives and experiences.
• Supporting visuals.  Include one or two impactful visuals, such as graphs, infographics, or highlighted metrics, that reinforce the narrative.
• Call to action (CTA).  If you do your job well, your audience will read (or watch) your case studies from beginning to end. They are interested in everything you've said. Now, what's the next step they should take to continue their relationship with you? Give people a simple action they can complete. 

Case studies are proven marketing strategies in a wide variety of B2B industries. Here are just a few examples of a case study:

• Amazon Web Services, Inc.  provides companies with cloud computing platforms and APIs on a metered, pay-as-you-go basis. This case study example illustrates the benefits Thomson Reuters experienced using AWS.
• LinkedIn Marketing Solutions combines captivating visuals with measurable results in the case study created for BlackRock. This case study illustrates how LinkedIn has contributed to the growth of BlackRock's brand awareness over the years. 
• Salesforce , a sales and marketing automation SaaS solutions provider, seamlessly integrates written and visual elements to convey its success stories with Pepe Jeans. This case study effectively demonstrates how Pepe Jeans is captivating online shoppers with immersive and context-driven e-commerce experiences through Salesforce.
• HubSpot offers a combination of sales and marketing tools. Their case study demonstrates the effectiveness of its all-in-one solutions. These typically focus on a particular client's journey and how HubSpot helped them achieve significant results.

There are two different types of case studies that businesses might utilize:

Written case studies 

Written case studies offer readers a clear visual representation of data, which helps them quickly identify and focus on the information that matters most. 

Printed versions of case studies find their place at events like trade shows, where they serve as valuable sales collateral to engage prospective clients.  Even in the digital age, many businesses provide case studies in PDF format or as web-based landing pages, improving accessibility for their audience. 

Note: Landing pages , in particular, offer the flexibility to incorporate rich multimedia content, including images, charts, and videos. This flexibility in design makes landing pages an attractive choice for presenting detailed content to the audience.

Written case study advantages

Here are several significant advantages to leveraging case studies for your company:

• Hyperlink accessibility.  Whether in PDF or landing page format, written case studies allow for embedded hyperlinks, offering prospects easy access to additional information and contact forms.
• Flexible engagement.  Unlike video case studies, which may demand in-person arrangements, written case studies can be conducted via phone or video streaming, reducing customer commitment and simplifying scheduling.
• Efficient scanning . Well-structured written case studies with a scannable format cater to time-strapped professionals. Charts and callout boxes with key statistics enhance the ease of information retrieval.
• Printable for offline use.  Written case studies can be effortlessly printed and distributed at trade shows, sales meetings, and live events. This tangible format accommodates those who prefer physical materials and provides versatility in outreach, unlike video content, which is less portable.

Written case study disadvantages

Here are some drawbacks associated with the use of case studies:

• Reduced emotional impact.  Written content lacks the emotional punch of live video testimonials, which engage more senses and emotions, making a stronger connection.
• Consider time investment.  Creating a compelling case study involves editing, proofreading, and design collaboration, with multiple revisions commonly required before publication.
• Challenges in maintaining attention.  Attention spans are short in today's ad-saturated world. Using graphics, infographics, and videos more often is more powerful to incite the right emotions in customers.

Video case studies

Video case studies are the latest marketing trend. Unlike in the past, when video production was costly, today's tools make it more accessible for users to create and edit their videos. However, specific technical requirements still apply.

Like written case studies, video case studies delve into a specific customer's challenges and how your business provides solutions. Yet, the video offers a more profound connection by showcasing the person who faced and conquered the problem.

Video case studies can boost brand exposure when shared on platforms like YouTube. For example, Slack's engaging case study video with Sandwich Video illustrates how Slack transformed its workflow and adds humor, which can be challenging in written case studies focused on factual evidence.

Source : YouTube

This video case study has garnered nearly a million views on YouTube.

Video case study advantages

Here are some of the top advantages of video case studies. While video testimonials take more time, the payoff can be worth it. 

• Humanization and authenticity.  Video case studies connect viewers with real people, adding authenticity and fostering a stronger emotional connection.
• Engaging multiple senses.  They engage both auditory and visual senses, enhancing credibility and emotional impact. Charts, statistics, and images can also be incorporated.
• Broad distribution.  Videos can be shared on websites, YouTube, social media, and more, reaching diverse audiences and boosting engagement, especially on social platforms.

Video case study disadvantages

Before fully committing to video testimonials, consider the following:

• Technical expertise and equipment.  Video production requires technical know-how and equipment, which can be costly. Skilled video editing is essential to maintain a professional image. While technology advances, producing amateurish videos may harm your brand's perception.
• Viewer convenience.  Some prospects prefer written formats due to faster reading and ease of navigation. Video typically requires sound, which can be inconvenient for viewers in specific settings. Many people may not have headphones readily available to watch your content.
• Demand on case study participants.  On-camera interviews can be time-consuming and location-dependent, making scheduling challenging for case study participants. Additionally, being on screen for a global audience may create insecurities and performance pressure.
• Comfort on camera.  Not everyone feels at ease on camera. Nervousness or a different on-screen persona can impact the effectiveness of the testimonial, and discovering this late in the process can be problematic.

Written or video case studies: Which is right for you?

Now that you know the pros and cons of each, how do you choose which is right for you?

One of the most significant factors in doing video case studies can be the technical expertise and equipment required for a high level of production quality. Whether you have the budget to do this in-house or hire a production company can be one of the major deciding factors.

Still, written or video doesn't have to be an either-or decision. Some B2B companies are using both formats. They can complement each other nicely, minimizing the downsides mentioned above and reaching your potential customers where they prefer.

Let's say you're selling IT network security. What you offer is invaluable but complicated. You could create a short (three- or four-minute) video case study to get attention and touch on the significant benefits of your services. This whets the viewer's appetite for more information, which they could find in a written case study that supplements the video.

Should you decide to test the water in video case studies, test their effectiveness among your target audience. See how well they work for your company and sales team. And, just like a written case study, you can always find ways to improve your process as you continue exploring video case studies.

Case studies offer several distinctive advantages, making them an ideal tool for businesses to market their products to customers. However, their benefits extend beyond these qualities. 

Here's an overview of all the advantages of case studies:

Valuable sales support

Case studies serve as a valuable resource for your sales endeavors. Buyers frequently require additional information before finalizing a purchase decision. These studies provide concrete evidence of your product or service's effectiveness, assisting your sales representatives in closing deals more efficiently, especially with customers with lingering uncertainties.

Validating your value

Case studies serve as evidence of your product or service's worth or value proposition , playing a role in building trust with potential customers. By showcasing successful partnerships, you make it easier for prospects to place trust in your offerings. This effect is particularly notable when the featured customer holds a reputable status.

Unique and engaging content

By working closely with your customer success teams, you can uncover various customer stories that resonate with different prospects. Case studies allow marketers to shape product features and benefits into compelling narratives. 

Each case study's distinctiveness, mirroring the uniqueness of every customer's journey, makes them a valuable source of relatable and engaging content. Storytelling possesses the unique ability to connect with audiences on an emotional level, a dimension that statistics alone often cannot achieve. 

Spotlighting valuable customers

Case studies provide a valuable platform for showcasing your esteemed customers. Featuring them in these studies offers a chance to give them visibility and express your gratitude for the partnership, which can enhance customer loyalty . Depending on the company you are writing about, it can also demonstrate the caliber of your business.

Now is the time to get SaaS-y news and entertainment with our 5-minute newsletter,   G2 Tea , featuring inspiring leaders, hot takes, and bold predictions. Subscribe below!

It's important to consider limitations when designing and interpreting the results of case studies. Here's an overview of the limitations of case studies:

Challenges in replication

Case studies often focus on specific individuals, organizations, or situations, making generalizing their findings to broader populations or contexts challenging. 

Time-intensive process

Case studies require a significant time investment. The extensive data collection process and the need for comprehensive analysis can be demanding, especially for researchers who are new to this method.

Potential for errors

Case studies can be influenced by memory and judgment, potentially leading to inaccuracies. Depending on human memory to reconstruct a case's history may result in variations and potential inconsistencies in how individuals recall past events. Additionally, bias may emerge, as individuals tend to prioritize what they consider most significant, which could limit their consideration of alternative perspectives.

Challenges in verification

Confirming results through additional research can present difficulties. This complexity arises from the need for detailed and extensive data in the initial creation of a case study. Consequently, this process requires significant effort and a substantial amount of time.

While looking at case studies, you may have noticed a quote. This type of quote is considered a testimonial, a key element of case studies.

If a customer's quote proves that your brand does what it says it will or performs as expected, you may wonder: 'Aren't customer testimonials and case studies the same thing?' Not exactly.

Testimonials are brief endorsements designed to establish trust on a broad scale. In contrast, case studies are detailed narratives that offer a comprehensive understanding of how a product or service addresses a specific problem, targeting a more focused audience. 

Crafting case studies requires more resources and a structured approach than testimonials. Your selection between the two depends on your marketing objectives and the complexity of your product or service.

Case in point!

Case studies are among a company's most effective tools. You're  well on your way to mastering them.

Today's buyers are tackling much of the case study research methodology independently. Many are understandably skeptical before making a buying decision. By connecting them with multiple case studies, you can prove you've gotten the results you say you can. There's hardly a better way to boost your credibility and persuade them to consider your solution.

Case study formats and distribution methods might change as technology evolves. However, the fundamentals that make them effective—knowing how to choose subjects, conduct interviews, and structure everything to get attention—will serve you for as long as you're in business. 

We covered a ton of concepts and resources, so go ahead and bookmark this page. You can refer to it whenever you have questions or need a refresher.

Dive into market research to uncover customer preferences and spending habits.

Kristen McCabe

Kristen’s is a former senior content marketing specialist at G2. Her global marketing experience extends from Australia to Chicago, with expertise in B2B and B2C industries. Specializing in content, conversions, and events, Kristen spends her time outside of work time acting, learning nature photography, and joining in the #instadog fun with her Pug/Jack Russell, Bella. (she/her/hers)

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How to Write a Case Study: The Compelling Step-by-Step Guide

Is there a poignant pain point that needs to be addressed in your company or industry? Do you have a possible solution but want to test your theory? Why not turn this drive into a transformative learning experience and an opportunity to produce a high-quality business case study? However, before that occurs, you may wonder how to write a case study.

You may also be thinking about why you should produce one at all. Did you know that case studies are impactful and the fifth most used type of content in marketing , despite being more resource-intensive to produce?

Below, we’ll delve into what a case study is, its benefits, and how to approach business case study writing:

Definition of a Written case study and its Purpose

A case study is a research method that involves a detailed and comprehensive examination of a specific real-life situation. It’s often used in various fields, including business, education, economics, and sociology, to understand a complex issue better. 

It typically includes an in-depth analysis of the subject and an examination of its context and background information, incorporating data from multiple sources, such as interviews, observations, and existing literature. 

The ultimate aim is to provide a rich and detailed account of a situation to identify patterns and relationships, generate new insights and understanding, illustrate theories, or test hypotheses.

Importance of Business Case Study Writing

As such an in-depth exploration into a subject with potentially far-reaching consequences, a case study has benefits to offer various stakeholders in the organisation leading it.

• Business Founders: Use business case study writing to highlight real-life examples of companies or individuals who have benefited from their products or services, providing potential customers with a tangible demonstration of the value their business can bring. It can be effective for attracting new clients or investors by showcasing thought leadership and building trust and credibility.
• Marketers through case studies and encourage them to take action: Marketers use a case studies writer to showcase the success of a particular product, service, or marketing campaign. They can use persuasive storytelling to engage the reader, whether it’s consumers, clients, or potential partners.
• Researchers: They allow researchers to gain insight into real-world scenarios, explore a variety of perspectives, and develop a nuanced understanding of the factors that contribute to success or failure. Additionally, case studies provide practical business recommendations and help build a body of knowledge in a particular field.

How to Write a Case Study – The Key Elements 

Considering how to write a case study can seem overwhelming at first. However, looking at it in terms of its constituent parts will help you to get started, focus on the key issue(s), and execute it efficiently and effectively.

Problem or Challenge Statement

A problem statement concisely describes a specific issue or problem that a written case study aims to address. It sets the stage for the rest of the case study and provides context for the reader. 

Here are some steps to help you write a case study problem statement:

• Identify the problem or issue that the case study will focus on.
• Research the problem to better understand its context, causes, and effects.
• Define the problem clearly and concisely. Be specific and avoid generalisations.
• State the significance of the problem: Explain why the issue is worth solving. Consider the impact it has on the individual, organisation, or industry.
• Provide background information that will help the reader understand the context of the problem.
• Keep it concise: A problem statement should be brief and to the point. Avoid going into too much detail – leave this for the body of the case study!

Here is an example of a problem statement for a case study:

“ The XYZ Company is facing a problem with declining sales and increasing customer complaints. Despite improving the customer experience, the company has yet to reverse the trend . This case study will examine the causes of the problem and propose solutions to improve sales and customer satisfaction. “

Solutions and interventions

Business case study writing provides a solution or intervention that identifies the best course of action to address the problem or issue described in the problem statement. 

Here are some steps to help you write a case study solution or intervention:

• Identify the objective , which should be directly related to the problem statement.
• Analyse the data, which could include data from interviews, observations, and existing literature.
• Evaluate alternatives that have been proposed or implemented in similar situations, considering their strengths, weaknesses, and impact.
• Choose the best solution based on the objective and data analysis. Remember to consider factors such as feasibility, cost, and potential impact.
• Justify the solution by explaining how it addresses the problem and why it’s the best solution with supportive evidence.
• Provide a detailed, step-by-step plan of action that considers the resources required, timeline, and expected outcomes.

Example of a solution or intervention for a case study:

“ To address the problem of declining sales and increasing customer complaints at the XYZ Company, we propose a comprehensive customer experience improvement program. “

“ This program will involve the following steps:

• Conducting customer surveys to gather feedback and identify areas for improvement
• Implementing training programs for employees to improve customer service skills
• Revising the company’s product offerings to meet customer needs better
• Implementing a customer loyalty program to encourage repeat business “

“ These steps will improve customer satisfaction and increase sales. We expect a 10% increase in sales within the first year of implementation, based on similar programs implemented by other companies in the industry. “

Possible Results and outcomes

Writing case study results and outcomes involves presenting the impact of the proposed solution or intervention. 

Here are some steps to help you write case study results and outcomes:

• Evaluate the solution by measuring its effectiveness in addressing the problem statement. That could involve collecting data, conducting surveys, or monitoring key performance indicators.
• Present the results clearly and concisely, using graphs, charts, and tables to represent the data where applicable visually. Be sure to include both quantitative and qualitative results.
• Compare the results to the expectations set in the solution or intervention section. Explain any discrepancies and why they occurred.
• Discuss the outcomes and impact of the solution, considering the benefits and drawbacks and what lessons can be learned.
• Provide recommendations for future action based on the results. For example, what changes should be made to improve the solution, or what additional steps should be taken?

Example of results and outcomes for a case study:

“ The customer experience improvement program implemented at the XYZ Company was successful. We found significant improvement in employee health and productivity. The program, which included on-site exercise classes and healthy food options, led to a 25% decrease in employee absenteeism and a 15% increase in productivity . “

“ Employee satisfaction with the program was high, with 90% reporting an improved work-life balance. Despite initial costs, the program proved to be cost-effective in the long run, with decreased healthcare costs and increased employee retention. The company plans to continue the program and explore expanding it to other offices .”

Case Study Key takeaways

Key takeaways are the most important and relevant insights and lessons that can be drawn from a case study. Key takeaways can help readers understand the most significant outcomes and impacts of the solution or intervention. 

Here are some steps to help you write case study key takeaways:

• Summarise the problem that was addressed and the solution that was proposed.
• Highlight the most significant results from the case study.
• Identify the key insights and lessons , including what makes the case study unique and relevant to others.
• Consider the broader implications of the outcomes for the industry or field.
• Present the key takeaways clearly and concisely , using bullet points or a list format to make the information easy to understand.

Example of key takeaways for a case study:

• The customer experience improvement program at XYZ Company successfully increased customer satisfaction and sales.
• Employee training and product development were critical components of the program’s success.
• The program resulted in a 20% increase in repeat business, demonstrating the value of a customer loyalty program.
• Despite some initial challenges, the program proved cost-effective in the long run.
• The case study results demonstrate the importance of investing in customer experience to improve business outcomes.

Steps for a Case Study Writer to Follow

If you still feel lost, the good news is as a case studies writer; there is a blueprint you can follow to complete your work. It may be helpful at first to proceed step-by-step and let your research and analysis guide the process:

• Select a suitable case study subject: Ask yourself what the purpose of the business case study is. Is it to illustrate a specific problem and solution, showcase a success story, or demonstrate best practices in a particular field? Based on this, you can select a suitable subject by researching and evaluating various options.
• Research and gather information: We have already covered this in detail above. However, always ensure all data is relevant, valid, and comes from credible sources. Research is the crux of your written case study, and you can’t compromise on its quality.
• Develop a clear and concise problem statement: Follow the guide above, and don’t rush to finalise it. It will set the tone and lay the foundation for the entire study.
• Detail the solution or intervention: Follow the steps above to detail your proposed solution or intervention.
• Present the results and outcomes: Remember that a case study is an unbiased test of how effectively a particular solution addresses an issue. Not all case studies are meant to end in a resounding success. You can often learn more from a loss than a win.
• Include key takeaways and conclusions: Follow the steps above to detail your proposed business case study solution or intervention.

Tips for How to Write a Case Study

Here are some bonus tips for how to write a case study. These tips will help improve the quality of your work and the impact it will have on readers:

• Use a storytelling format: Just because a case study is research-based doesn’t mean it has to be boring and detached. Telling a story will engage readers and help them better identify with the problem statement and see the value in the outcomes. Framing it as a narrative in a real-world context will make it more relatable and memorable.
• Include quotes and testimonials from stakeholders: This will add credibility and depth to your written case study. It also helps improve engagement and will give your written work an emotional impact.
• Use visuals and graphics to support your narrative: Humans are better at processing visually presented data than endless walls of black-on-white text. Visual aids will make it easier to grasp key concepts and make your case study more engaging and enjoyable. It breaks up the text and allows readers to identify key findings and highlights quickly.
• Edit and revise your case study for clarity and impact: As a long and involved project, it can be easy to lose your narrative while in the midst of it. Multiple rounds of editing are vital to ensure your narrative holds, that your message gets across, and that your spelling and grammar are correct, of course!

Our Final Thoughts

A written case study can be a powerful tool in your writing arsenal. It’s a great way to showcase your knowledge in a particular business vertical, industry, or situation. Not only is it an effective way to build authority and engage an audience, but also to explore an important problem and the possible solutions to it. It’s a win-win, even if the proposed solution doesn’t have the outcome you expect. So now that you know more about how to write a case study, try it or talk to us for further guidance.

Are you ready to write your own case study?

Begin by bookmarking this article, so you can come back to it. And for more writing advice and support, read our resource guides  and  blog content . If you are unsure, please reach out with questions, and we will provide the answers or assistance you need.

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5 Steps for Writing a Case Study for Business (+Templates)

Get professional tips for writing a case study that drives business impact. Learn the best format and research method to use alongside examples & templates.

7 minute read

helped business professionals at:

SHORT ANSWER

What is a case study.

• Open with an introductory overview
• Explain the problem in question
• Detail the solutions that solved the problem
• Refer to key results
• Finish with recommendations and next steps

Why you need a case study

“I climbed Mount Everest and I did it all by myself.” “Yeah mate, pics or it didn’t happen.” The same logic applies to case studies. In business, it’s “case studies or it didn’t happen.” A well-written case study legitimizes your product or services. It proves the impact your actions have on the bottom line and is the single most important element of building trust amongst prospective clients. But… How do you write a *perfect* case study? One that engages readers and makes them care about your offering and excited to work with you?

In business, a case study , or customer success story, is a marketing tool that showcases how your product or service helped clients overcome business challenges. It uses statistics, quotes, and specific examples to convincingly highlight your ability to produce results.

What is the purpose of a case study?

The purpose of a case study, usually, is to provide your prospective clients with specific examples of how your products or services can help solve business problems they might be facing.

Case studies legitimize your business activities allowing you to go beyond explaining what you do and focus on how well you do it. (And, in case you were wondering just HOW important case studies are, here’s an item of data to ponder: according to a DemandGen report , 78% of B2B buyers want to review case studies before making a purchase decision. Another study by Uplift found that at the end of 2023, f or the third year in a row, marketers ranked case studies the #1 most effective marketing tactic to increase sales—ahead of general website content, SEO, blog posts, social media, paid ads and other tactics. )

There’s no magic behind it. Just a proven, simple formula I’m about to share with you. Spend the next 7 minutes reading this guide and you’ll learn how to write case studies better than any case study you’ve created in the past. Important caveat: this article explains how to write a case study for business purposes. If you’re interested in writing research case studies for academia, refer to this excellent guide by University of Southern California. If, in turn, you’re struggling with putting together a medical case study, here’s a fantastic 101 by the BMJ . I’m not going to pretend I know better than these guys do.

For your reference, here’s an example of our very own case study, showing how, at Storydoc, we helped the Spot company boost some of their key metrics: Learn How Spot by NetApp boosted their conversion rates 2x.

Spot's team used this deck to boost their conversion 2x

By drawing the bigger picture even deep-tech software products can be easily explained.

Browse interactive case study templates

No matter how great the contents of your case study might be, if you fail to present it in an eye-pleasing way, most likely, no one will really read it. The good news? I’ve put together a gallery of the most professional, attention-grabbing case study templates available online. You can find it here: Case Study Templates & Design Tips Or, take a shortcut to great case study design and use our presentation maker . Have a look below to see what your case study might look like.

And now, let’s get to the case study 101. (If you’re only interested in a specific section of a case study, simply click on a jump-to link in the table of contents below.

Here's how to write a case study:

1. Open with an introductory overview

The last thing you want is for someone to open your case study, give it a quick glance, and decide to skip. See— People don’t usually read case studies. At least not immediately. First, they skim the contents to see if the subject is relevant enough. How to make sure your case study sticks? At the beginning, place an introductory overview (also called an “executive summary”). Provide an overview of the whole case. It’s not supposed to be a catchy intro but a full synopsis, detailing the problem at hand, your assumptions, the solutions implemented, and the results achieved.

How to write a case study introduction?

Introduce the purpose of the case study—specify exactly what you were aiming to achieve.

Define the problem or the most significant challenge. For instance, low conversion rates, a technological issue or high costs. (It could also be a combination of such factors!)

Explain briefly what the solution to the problem was.

Share the most important results your actions produced. Don’t go into too much detail, a few key points will do. It’s best if you can quantify the results: numbers pop!

Keep it short. Usually, 2–4 paragraphs + a few bullet points with key results will do.

While, as its name implies, this section comes at the beginning of your case study, write it last. First, craft the rest of your document, then pick the most important bits and compile them into the introductory overview.

2. Explain the problem in question

“Adam caught a flat tire. In the middle of the desert. He had no spare, no signal, no food, and only enough water to keep him alive for 48 hours.” Oh dear, poor Adam! What could possibly be done to help him?! See, in your case study, make the client seem like Adam so that, later on, you can paint your company like the miraculous savior. Of course, I’m exaggerating, but only so much. The purpose of the “problem” section in a case study is to arouse emotions from the readers. Ideally, in such a way that they can picture themselves as Adam. Highlight a problem your product or services solve and present an example of when that problem was troubling a client really badly.

How to write a “problem” section in a case study?

In a single sentence, describe your customer’s business challenges and objectives.

Explain the problem your customer faced that prevented them from achieving those objectives prior to working with you.

If that was the case, mention other solutions your client experimented with that didn’t work out and explain why.

Make it clear how the issue or problem impacted the client’s business results so that it’s easy to understand why a solution was badly needed.

3. Detail the solutions implemented to solve the problem

Here comes the moment to toot your own horn a bit (and also that moment when you can get slightly technical). Present your solutions in reference to the issue your client was dealing with and make it obvious that those are easily replicable for all future cases. Of course, the exact formula for this section will depend on your industry and mode of operation. Sometimes a 2–3 paragraph summary will be enough, in other cases, you’ll need to include more detailed technical specs regarding the solution you implemented.

How to write a solutions section in a case study?

Focus on your customer’s experience in using your product or services.

Explain the process: say how long it took to get the solution up and running and what teams on your customer’s end were involved.

Highlight the features of your product or service that turned out to be the most beneficial to your customer.

If possible, attach or link to relevant assets that will work as real-life examples of your solution (unless, of course, the information is highly sensitive).

Always run your case study by your client’s marketing team before you go live. Even if you’re using direct quotes or verifiable results, it’s ultimately their decision whether or not to make certain information freely available.

4. Refer to key results

In business, nothing speaks louder than ROI and you know it. Prospective customers reading your case study won’t be bothered to take notice of your state-of-the-art technology or innovative approach. Neither will they care about your past customers’ happiness. What they want to know is this: Will that help me save or make money? When writing a case study, your job is to present results in a way that answers the above question with a resounding YES. You need to make it blatantly obvious that your solutions heavily impact the bottom line of the client in question and that such results are easily replicable.

Here’s how to write about results:

In a few bullet points, list numerical results your solution delivered to the client.

Ideally, you’ll want to include revenue-related data: increase in clients’ base, more demos booked, higher conversion rates, or optimized pricing.

If you can’t (or aren’t allowed to) share hard sales numbers, refer to softer KPIs: time saved, customer happiness scores, expanding the community, or enhancing brand visibility.

If possible, by all means include quotes from your client. Results should speak for themselves, obviously, but showing the real human whose problems you solved makes for a much more powerful narrative. Plus, it further adds credibility to the case study. Start by preparing a list of powerful case study questions to guide your client interviews.8

5. Finish with recommendations and next steps

Everyone enjoys a solid epilogue. To end on a high note, include a list of key findings from your case study. Even if a given reader won’t decide to get in touch with you, at least you’ll provide them with a valuable source of knowledge—sometimes that’s enough to keep your company top of mind in the future. Plus, if you’re planning to continue working with the subject of your case study, definitely mention that! It shows that your support is valuable enough to warrant long-term collaboration, not just a one-off endeavor. Now, not every case study requires a call to action (especially if your main purpose is to inform and educate rather than convert, which is okay, too), but for those more commercially-oriented ones, do add it. Make your CTA singular and clear —if the most desired action is to reach out to you, leave your contact details, if you’d rather direct prospects to a landing page or a welcome screen, add a button.

And that’s a wrap!

Here are the key points to keep in mind when writing a case study:

Put an introductory overview at the beginning.

Present the problem you were solving and your exact solutions to that problem.

Include numerical, verifiable results your product or services delivered for the client.

Explain what the next steps are, especially if you plan to continue working with the client.

Finish with a strong, clear CTA, making it easy for prospects to reach out to you.

Thanks for reading the guide. Keeping my fingers crossed for your case study and wishing many successful cases so that you’ll always have something to write about.

Hi, I'm John, Editor-in-chief at Storydoc. As a content marketer and digital writer specializing in B2B SaaS, my main goal is to provide you with up-to-date tips for effective business storytelling and equip you with all the right tools to enable your sales efforts.

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Your Step-By-Step Guide To Writing a Case Study

Creating a case study is both an art and a science. It requires making an in-depth exploration of your chosen subject in order to extract meaningful insights and understand the dynamics that more general surveys or statistical research might not uncover. At the same time, your case study also needs to be a compelling read to ensure those insights get attention from other people!

Unsurprisingly, the prospect of crafting an effective case study can be daunting. It calls for strategic planning, careful organization, and clear communication, all of which can be challenging even for experienced researchers. That's why we've created this step-by-step guide, which breaks the process down into manageable steps, demystifying the journey from defining your research question to sharing your findings. Whether you're a seasoned researcher or a first-timer, this guide aims to equip you with the necessary tools and tips to create a case study that's not just informative, but also engaging and impactful.

Are you ready to unlock the potential of case studies? Let's dive in!

What is a case study?

First, it's important to understand what a case study is – and what it isn't.

A case study is a thorough exploration of a specific subject or event over a certain time frame. Case studies are utilized in numerous fields, including sociology, psychology, education, anthropology, business, and the health sciences, and employ various research techniques to shed light on complex issues.

A case study does not provide absolute proof or conclusions that can be universally applied. Because it concentrates on one particular case or just a few cases, the findings might not apply to different contexts or subjects. Case studies also aren't ideal for determining cause-and-effect relationships as they do not use controlled conditions to separate and measure the impacts of different factors. Lastly, it must be said that a case study isn't just a random assortment of facts or observations; it necessitates a clear research question, a methodical approach to data collection and analysis, and a thoughtful interpretation of the results.

Getting started

Now that we've established the definition and purpose of a case study, let's explore the process by which one is created. You can produce a case study by following these nine steps:

1. Define the purpose of your case study

Before you start writing a case study, you need to define its purpose clearly. Ask yourself: What is the research question or problem you aim to solve? What insights are you looking to uncover? Your goals will guide your research design and influence your choice of case. This initial stage of introspection and clarification is crucial as it acts as a roadmap for your study.

2. Select the case to study

Once you've defined your research objective, the next step is to choose a suitable case that can help answer your research question. This might be a unique, critical, or representative instance. Unique cases offer the opportunity to observe and analyze a situation that is unusual or not well-understood. In contrast, a representative or typical case is often chosen because it represents other cases or a broader phenomenon.

In any case, be sure to justify your choice. Explain why the case is of interest and how it can contribute to the knowledge or understanding of the issue at hand. For instance, if you're studying the effects of corporate restructuring on employee morale, you might choose to focus on a company that recently underwent a significant restructure.

3. Conduct a thorough literature review

Performing a literature review involves a careful examination of relevant scholarly articles, books, and other sources related to your research question or problem. In the process, you identify gaps in the current knowledge and determine how your case study can address them. By critically examining existing research, you will not only gain a comprehensive understanding of your chosen topic but also be able to refine your research question or hypothesis, if necessary.

4. Choose a methodological approach

The methodological approach used in your case study will depend on your research objectives and the nature of the case. Methodologies that can be employed in case studies include qualitative, quantitative, and mixed methods .

Qualitative methods are often used when the goal is to explore, understand, or interpret certain phenomena. These involve approaches like interviews, focus groups, or ethnography. Quantitative methods, on the other hand, are used when the goal is to test hypotheses or examine relationships between variables. Quantitative approaches often include experiments. Also, surveys may be either qualitative or quantitative depending on the question design.

You may choose to use a combination of qualitative and quantitative methods (mixed methods) if it suits your research objectives.

5. Collect and organize your data

Data collection should be systematic and organized to maintain the integrity and reliability of your research. You need to plan how you will record and store your data to ensure that it's accessible and usable.

If you're conducting interviews or observations, consider using recording devices (with participant consent) to capture the data accurately. In addition, you may want to transcribe the recorded material for easier analysis. If you're using documents or archival records, develop a system for coding and categorizing the data.

6. Analyze the data

Analysis involves interpreting your data to draw out meaningful insights; it is in this stage that your findings start to take shape. Depending on the nature of your data and your research question, you might use any of a variety of analysis methods. For qualitative data, you might employ thematic analysis to identify key themes or grounded theory to generate a new theoretical framework. For quantitative data, you might use statistical analysis to identify patterns or correlations.

Always be open to unexpected findings. Your initial hypotheses might not be supported, or you might uncover new insights that you hadn't initially considered. Remember that all data, whether they fit neatly into your analysis or not, provide valuable insights and contribute to the holistic understanding of your case.

7. Write the case study report

After analyzing the data, it's finally time to compose your case study. In terms of structure, a typical case study might consist of an introduction, background information, the collected data (results), analysis of that data, and the conclusion. Here's a brief breakdown of each section:

• Introduction: The introduction should be brief but engaging, providing a clear statement of the research question or problem, explaining why the case was chosen, and outlining what the case study will cover.
• Background: The background provides the context for your case. Describe the case, its history, and any relevant information that will help readers understand the situation.
• Results: This section should provide a comprehensive account of what you found, without interpretation or opinion. Present your findings in a clear, organized manner. Use visuals such as charts or graphs if they aid comprehension.
• Analysis: This section should provide your interpretations and arguments. Discuss the patterns, themes, or relationships you've identified in your data. Explain what these findings mean in relation to your research question.
• Conclusion: Finally, summarize the key insights from your case study along with their implications. Discuss the limitations of your study and propose avenues for future research.

8. Review and revise

The process of writing a case study doesn't actually end when the report is written; you also need to review your writing for coherence, clarity, and correctness. Don't underestimate the importance of this step! Make sure the information flows logically and that your arguments are well-supported. Check for any grammar or spelling errors. Having a peer or mentor review your work can be incredibly helpful as they provide a fresh perspective and can catch mistakes you might have missed.

9. Get approval if required

If your case study involves human subjects, you may need to obtain approval from an ethical review board. You'll also need to obtain informed consent from your subjects and ensure you respect their privacy and confidentiality throughout the research process. Always follow your institution's ethical guidelines and any other relevant legislation .

Practical tips for writing a compelling case study

Getting through all those steps can feel like a formidable challenge, but here are some practical tips to make the process more manageable:

Be systematic and organized

Given the importance of detail in case studies, it's vital to be systematic and organized from the get-go. This means keeping meticulous records of your data, your sources, and any changes to your research design. A good practice is to maintain a research journal or log where you can record your process, thoughts, and reflections.

In addition, use technology to your advantage. Digital tools like citation managers can help you keep track of your sources and make formatting references a breeze, while spreadsheet or database software can assist in managing and organizing your data. Developing a consistent system for labeling and storing information at the outset will save you time and effort later when you need to retrieve data for analysis.

Stay focused

One common pitfall in research and writing is loss of focus: getting sidetracked by interesting but ultimately irrelevant digressions, which can be very easy, especially when you're dealing with a rich and complex case. Always remember your research question and objectives, and let these guide your study at every step. It's perfectly acceptable – and in fact advisable – to delineate what your study will not cover. Setting clear boundaries can help you stay focused and manage the scope of your study effectively.

Use visual aids

Visual aids such as charts, diagrams, or photographs can greatly enhance your case study. They provide readers with a break from the monotony of text and can communicate complex data or relationships more easily. For instance, if you're presenting a lot of numerical data, consider using a chart or graph. If you're describing a process or sequence of events, portraying it in a flowchart or timeline might be useful. Remember, the goal is to aid comprehension, so make sure your visual aids are clear, well-labeled, and integrated into the text.

Include direct quotes

If your case study involves interviews, including direct quotes can add depth and a sense of the personal to your findings. They provide readers with a firsthand perspective and make your case study more engaging.

When using quotes, be sure to integrate them smoothly into your text. Provide enough context so readers understand the quote's relevance. Also, remember to adhere to ethical guidelines– always respect confidentiality and anonymity agreements.

Maintain ethical standards

Ethics is a fundamental consideration in all research, including case studies. Ensure you have proper consent from participants, respect their privacy, and accurately present your findings without manipulation.

Misrepresenting data or failing to respect participants' rights can lead to serious ethical violations. Always follow your institution's ethical guidelines and any other relevant legislation. If in doubt, seek advice from a supervisor or your institution's ethics committee.

Acknowledge limitations

Every research study has limitations, which could relate to the research design, data collection methods, or other aspects of the study. Being transparent about the limitations of your study can enhance its credibility; moreover, not only does identifying limitations demonstrate your critical thinking and honesty, but it also helps readers accurately interpret your findings.

Finally, acknowledging the limitations of your work helps to set the stage for further research. By identifying aspects that your study couldn't address, you provide other researchers with avenues for building on your findings.

Learn from examples

Before you start writing your case study, it can be helpful to review some published case studies in your field. Different fields may have different conventions, and familiarizing yourself with case studies in your own field can help guide your writing. Look at the structure, tone, and style. Pay attention to how the authors present and analyze data, and how they link their findings back to the research question. You can also learn a lot from the strengths and weaknesses of previously published works. However, remember to develop your own unique voice and perspective – don't just mimic what others have done.

Design for triangulation

Triangulation involves using multiple data sources or methods to gain a more comprehensive and balanced understanding of your research topic. By coming at your research question from multiple directions, such as by examining different datasets or using different methods, you can increase the validity of your results and gain more nuanced insights.

For example, if you're studying the impact of a new teaching method in a school, you might observe classes, interview teachers, and also survey students. Each method will provide a slightly different perspective, and together, they allow you to develop a more complete picture of the teaching method's impact.

Practice reflexivity

Reflexivity involves reflecting on how your assumptions, values, or experiences might influence your research process and interpretations. As a researcher, it's essential to be aware of your potential biases and how they might shape your study.

Consider keeping a reflexivity journal where you can note your thoughts, feelings, and reflections throughout the research process. This practice can help you stay aware of your biases and ensure your research is as objective and balanced as possible.

Write for your audience

Always make sure that your writing is on target for your intended audience. If you're writing for an academic audience, for example, you'll likely use a more formal tone and include more detailed methodological information. If you're writing for practitioners or a general audience, you might use a more accessible language and focus more on practical implications.

Remember to define any technical terms or jargon, and provide sufficient context so your readers can understand your research. The goal is to communicate your findings effectively, regardless of who your readers are.

Seek feedback

Feedback is valuable for improving your case study. Consider sharing drafts with your peers, mentors, or supervisors and asking for their input. Fresh eyes can provide different perspectives, catch errors, or suggest ways to strengthen your arguments.

Remember, feedback is not personal; it's about improving your work. Be open to critique and willing to revise your work based on the feedback you receive.

Writing a case study is a meticulous process that requires clear purpose, careful planning, systematic data collection, and thoughtful analysis. Although it can be time-consuming, the rich, detailed insights a well-executed case study can provide make this study design an invaluable tool in research.

By following this guide and adopting its practical tips, you will be well on your way to crafting a compelling case study that contributes meaningful insights to your chosen field. Good luck with your research journey!

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Home » Case Study – Methods, Examples and Guide

Case Study – Methods, Examples and Guide

Table of Contents

A case study is a research method that involves an in-depth examination and analysis of a particular phenomenon or case, such as an individual, organization, community, event, or situation.

It is a qualitative research approach that aims to provide a detailed and comprehensive understanding of the case being studied. Case studies typically involve multiple sources of data, including interviews, observations, documents, and artifacts, which are analyzed using various techniques, such as content analysis, thematic analysis, and grounded theory. The findings of a case study are often used to develop theories, inform policy or practice, or generate new research questions.

Types of Case Study

Types and Methods of Case Study are as follows:

Single-Case Study

A single-case study is an in-depth analysis of a single case. This type of case study is useful when the researcher wants to understand a specific phenomenon in detail.

For Example , A researcher might conduct a single-case study on a particular individual to understand their experiences with a particular health condition or a specific organization to explore their management practices. The researcher collects data from multiple sources, such as interviews, observations, and documents, and uses various techniques to analyze the data, such as content analysis or thematic analysis. The findings of a single-case study are often used to generate new research questions, develop theories, or inform policy or practice.

Multiple-Case Study

A multiple-case study involves the analysis of several cases that are similar in nature. This type of case study is useful when the researcher wants to identify similarities and differences between the cases.

For Example, a researcher might conduct a multiple-case study on several companies to explore the factors that contribute to their success or failure. The researcher collects data from each case, compares and contrasts the findings, and uses various techniques to analyze the data, such as comparative analysis or pattern-matching. The findings of a multiple-case study can be used to develop theories, inform policy or practice, or generate new research questions.

Exploratory Case Study

An exploratory case study is used to explore a new or understudied phenomenon. This type of case study is useful when the researcher wants to generate hypotheses or theories about the phenomenon.

For Example, a researcher might conduct an exploratory case study on a new technology to understand its potential impact on society. The researcher collects data from multiple sources, such as interviews, observations, and documents, and uses various techniques to analyze the data, such as grounded theory or content analysis. The findings of an exploratory case study can be used to generate new research questions, develop theories, or inform policy or practice.

Descriptive Case Study

A descriptive case study is used to describe a particular phenomenon in detail. This type of case study is useful when the researcher wants to provide a comprehensive account of the phenomenon.

For Example, a researcher might conduct a descriptive case study on a particular community to understand its social and economic characteristics. The researcher collects data from multiple sources, such as interviews, observations, and documents, and uses various techniques to analyze the data, such as content analysis or thematic analysis. The findings of a descriptive case study can be used to inform policy or practice or generate new research questions.

Instrumental Case Study

An instrumental case study is used to understand a particular phenomenon that is instrumental in achieving a particular goal. This type of case study is useful when the researcher wants to understand the role of the phenomenon in achieving the goal.

For Example, a researcher might conduct an instrumental case study on a particular policy to understand its impact on achieving a particular goal, such as reducing poverty. The researcher collects data from multiple sources, such as interviews, observations, and documents, and uses various techniques to analyze the data, such as content analysis or thematic analysis. The findings of an instrumental case study can be used to inform policy or practice or generate new research questions.

Case Study Data Collection Methods

Here are some common data collection methods for case studies:

Interviews involve asking questions to individuals who have knowledge or experience relevant to the case study. Interviews can be structured (where the same questions are asked to all participants) or unstructured (where the interviewer follows up on the responses with further questions). Interviews can be conducted in person, over the phone, or through video conferencing.

Observations

Observations involve watching and recording the behavior and activities of individuals or groups relevant to the case study. Observations can be participant (where the researcher actively participates in the activities) or non-participant (where the researcher observes from a distance). Observations can be recorded using notes, audio or video recordings, or photographs.

Documents can be used as a source of information for case studies. Documents can include reports, memos, emails, letters, and other written materials related to the case study. Documents can be collected from the case study participants or from public sources.

Surveys involve asking a set of questions to a sample of individuals relevant to the case study. Surveys can be administered in person, over the phone, through mail or email, or online. Surveys can be used to gather information on attitudes, opinions, or behaviors related to the case study.

Artifacts are physical objects relevant to the case study. Artifacts can include tools, equipment, products, or other objects that provide insights into the case study phenomenon.

How to conduct Case Study Research

Conducting a case study research involves several steps that need to be followed to ensure the quality and rigor of the study. Here are the steps to conduct case study research:

• Define the research questions: The first step in conducting a case study research is to define the research questions. The research questions should be specific, measurable, and relevant to the case study phenomenon under investigation.
• Select the case: The next step is to select the case or cases to be studied. The case should be relevant to the research questions and should provide rich and diverse data that can be used to answer the research questions.
• Collect data: Data can be collected using various methods, such as interviews, observations, documents, surveys, and artifacts. The data collection method should be selected based on the research questions and the nature of the case study phenomenon.
• Analyze the data: The data collected from the case study should be analyzed using various techniques, such as content analysis, thematic analysis, or grounded theory. The analysis should be guided by the research questions and should aim to provide insights and conclusions relevant to the research questions.
• Draw conclusions: The conclusions drawn from the case study should be based on the data analysis and should be relevant to the research questions. The conclusions should be supported by evidence and should be clearly stated.
• Validate the findings: The findings of the case study should be validated by reviewing the data and the analysis with participants or other experts in the field. This helps to ensure the validity and reliability of the findings.
• Write the report: The final step is to write the report of the case study research. The report should provide a clear description of the case study phenomenon, the research questions, the data collection methods, the data analysis, the findings, and the conclusions. The report should be written in a clear and concise manner and should follow the guidelines for academic writing.

Examples of Case Study

Here are some examples of case study research:

• The Hawthorne Studies : Conducted between 1924 and 1932, the Hawthorne Studies were a series of case studies conducted by Elton Mayo and his colleagues to examine the impact of work environment on employee productivity. The studies were conducted at the Hawthorne Works plant of the Western Electric Company in Chicago and included interviews, observations, and experiments.
• The Stanford Prison Experiment: Conducted in 1971, the Stanford Prison Experiment was a case study conducted by Philip Zimbardo to examine the psychological effects of power and authority. The study involved simulating a prison environment and assigning participants to the role of guards or prisoners. The study was controversial due to the ethical issues it raised.
• The Challenger Disaster: The Challenger Disaster was a case study conducted to examine the causes of the Space Shuttle Challenger explosion in 1986. The study included interviews, observations, and analysis of data to identify the technical, organizational, and cultural factors that contributed to the disaster.
• The Enron Scandal: The Enron Scandal was a case study conducted to examine the causes of the Enron Corporation’s bankruptcy in 2001. The study included interviews, analysis of financial data, and review of documents to identify the accounting practices, corporate culture, and ethical issues that led to the company’s downfall.
• The Fukushima Nuclear Disaster : The Fukushima Nuclear Disaster was a case study conducted to examine the causes of the nuclear accident that occurred at the Fukushima Daiichi Nuclear Power Plant in Japan in 2011. The study included interviews, analysis of data, and review of documents to identify the technical, organizational, and cultural factors that contributed to the disaster.

Application of Case Study

Case studies have a wide range of applications across various fields and industries. Here are some examples:

Business and Management

Case studies are widely used in business and management to examine real-life situations and develop problem-solving skills. Case studies can help students and professionals to develop a deep understanding of business concepts, theories, and best practices.

Case studies are used in healthcare to examine patient care, treatment options, and outcomes. Case studies can help healthcare professionals to develop critical thinking skills, diagnose complex medical conditions, and develop effective treatment plans.

Case studies are used in education to examine teaching and learning practices. Case studies can help educators to develop effective teaching strategies, evaluate student progress, and identify areas for improvement.

Social Sciences

Case studies are widely used in social sciences to examine human behavior, social phenomena, and cultural practices. Case studies can help researchers to develop theories, test hypotheses, and gain insights into complex social issues.

Law and Ethics

Case studies are used in law and ethics to examine legal and ethical dilemmas. Case studies can help lawyers, policymakers, and ethical professionals to develop critical thinking skills, analyze complex cases, and make informed decisions.

Purpose of Case Study

The purpose of a case study is to provide a detailed analysis of a specific phenomenon, issue, or problem in its real-life context. A case study is a qualitative research method that involves the in-depth exploration and analysis of a particular case, which can be an individual, group, organization, event, or community.

The primary purpose of a case study is to generate a comprehensive and nuanced understanding of the case, including its history, context, and dynamics. Case studies can help researchers to identify and examine the underlying factors, processes, and mechanisms that contribute to the case and its outcomes. This can help to develop a more accurate and detailed understanding of the case, which can inform future research, practice, or policy.

Case studies can also serve other purposes, including:

• Illustrating a theory or concept: Case studies can be used to illustrate and explain theoretical concepts and frameworks, providing concrete examples of how they can be applied in real-life situations.
• Developing hypotheses: Case studies can help to generate hypotheses about the causal relationships between different factors and outcomes, which can be tested through further research.
• Providing insight into complex issues: Case studies can provide insights into complex and multifaceted issues, which may be difficult to understand through other research methods.
• Informing practice or policy: Case studies can be used to inform practice or policy by identifying best practices, lessons learned, or areas for improvement.

Advantages of Case Study Research

There are several advantages of case study research, including:

• In-depth exploration: Case study research allows for a detailed exploration and analysis of a specific phenomenon, issue, or problem in its real-life context. This can provide a comprehensive understanding of the case and its dynamics, which may not be possible through other research methods.
• Rich data: Case study research can generate rich and detailed data, including qualitative data such as interviews, observations, and documents. This can provide a nuanced understanding of the case and its complexity.
• Holistic perspective: Case study research allows for a holistic perspective of the case, taking into account the various factors, processes, and mechanisms that contribute to the case and its outcomes. This can help to develop a more accurate and comprehensive understanding of the case.
• Theory development: Case study research can help to develop and refine theories and concepts by providing empirical evidence and concrete examples of how they can be applied in real-life situations.
• Practical application: Case study research can inform practice or policy by identifying best practices, lessons learned, or areas for improvement.
• Contextualization: Case study research takes into account the specific context in which the case is situated, which can help to understand how the case is influenced by the social, cultural, and historical factors of its environment.

Limitations of Case Study Research

There are several limitations of case study research, including:

• Limited generalizability : Case studies are typically focused on a single case or a small number of cases, which limits the generalizability of the findings. The unique characteristics of the case may not be applicable to other contexts or populations, which may limit the external validity of the research.
• Biased sampling: Case studies may rely on purposive or convenience sampling, which can introduce bias into the sample selection process. This may limit the representativeness of the sample and the generalizability of the findings.
• Subjectivity: Case studies rely on the interpretation of the researcher, which can introduce subjectivity into the analysis. The researcher’s own biases, assumptions, and perspectives may influence the findings, which may limit the objectivity of the research.
• Limited control: Case studies are typically conducted in naturalistic settings, which limits the control that the researcher has over the environment and the variables being studied. This may limit the ability to establish causal relationships between variables.
• Time-consuming: Case studies can be time-consuming to conduct, as they typically involve a detailed exploration and analysis of a specific case. This may limit the feasibility of conducting multiple case studies or conducting case studies in a timely manner.
• Resource-intensive: Case studies may require significant resources, including time, funding, and expertise. This may limit the ability of researchers to conduct case studies in resource-constrained settings.

About the author

Muhammad Hassan

Researcher, Academic Writer, Web developer

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How To Write a Case Study: a Helpful Step by Step Guide

Are you wondering how to write a case study? Take a few steps and case study examples you can use.

There’s a saying that you should show your story, not tell it. One of the best ways to show your story is to use a case study. There are lots of types of case studies. You might be interested in a business case study format, or you might be interested in a medical case study. You might even be interested in infographics that can help you augment your case study.

A case study should be a real-life example of a theme, principle, or strategy in action. A robust case study analysis should support your point of view and provide evidence for your argument. If you are interested in writing case studies, take a look at a few steps to follow.

Materials Needed

Study shows eating a healthy diet reduces risk of heart attack, case study shows effective copywriting boosts conversion rate, step 2: provide an abstract at the top, step 3: introduce the client, step 4: state the problem, step 5: state how the client found you, step 6: include information related to strategic approach, step 7: showcase the results, step 8: wrap-up and future directions, step 9: proofread your work.

To write a successful case study, you need several materials. They include:

• A computer with a strong internet connection for research purposes
• Research notes
• Graphs and charts
• Paper and writing utensils, such as pens and pencils
• Notes and recordings from interviews
• Required outlines or templates

Once you have collected the necessary materials, you can start the writing process.

Step 1: Develop a Compelling Headline

First, you need to develop a compelling headline. Remember that there is never a second chance to make a first impression. Therefore, your headline needs to include the essential information from the case study. A few tips for developing a compelling headline include:

• You must include all the necessary information, but a shorter headline is better.
• Try to put the most important words at the front of the headline.
• Read the headline out loud to make sure it makes sense.
• If you want to provide a subtitle with supporting details, you can do so, but it is unnecessary.
• If you have a quote from a customer you want to include, you can add this, but it is not required.

Here are a few sample headlines you may want to model your headline off of. A few examples include:

This is an excellent example headline because it is short, sweet, and to the point. The audience doesn’t have to wonder what the case study is about. Everything is included in the headline.

This is another compelling headline for a potential marketing case study. It says precisely what the case study demonstrates and invites the reader to learn more about what is defined as effective copywriting. You might also find our explainer on how to write a hypothesis useful.

Before diving into your case study’s details, you need to place an abstract at the top of the research paper. Looking at any scientific research paper, you will see an abstract at the top. It would help if you used this as a model for the abstract you will place at the top of your case study.

You need to place several vital pieces of information at the top of the case study. They include:

• Make sure you include the client’s name. Remember to ask the client for permission before including their results in your case study.
• You could also include the industry in which the client works. For example, is the client a financial company? Is the client a marketing company? Again, make sure to mention the industry.
• Do not forget to mention the product or service used. What are you trying to showcase? Mention the specific product or service at the top of the case study.
• If you have quick results, make sure to list them here. If you have infographics or graphs, be sure to reserve them for later areas of the case study. Include the actual results to convince the reader to keep reading.

If someone does not feel like reading the entire case study, they should be able to read the abstract and figure out what product or service you are promoting and why it is beneficial. 

You may want to provide a quick summary of what the client does. It should only last a few sentences but mention the client’s industry and what they provide. Here are a few sample client summaries you may want to use:

• “Our client is a leading family medicine practice that serves patients of all ages in the local area. The client provides both acute and preventative care.”
• “Our client is a local credit union that provides checking and savings account services. The client also provides loan services, such as auto loans and home loans.”

You can use these two examples from different industries to model your client description. 

Just beneath the section introducing the client, you can include information about the problem you were tasked to address. For example, why did the client call you? What were their concerns?

A few examples of problem statements you may want to mention in your case study include:

• “Our client was having a hard time shortening customer response time. Finally, the client realized that it took customers, on average, more than two hours to get a response to their concerns.”
• “Our client couldn’t figure out why their low conversion rates. Even though there was plenty of traffic going to the website, not enough people were reaching out to the business itself to learn more about the products and services offered. Less than one percent of people visiting the website were calling or emailing the business.” 

You may find it easier to include quotes from the client in this section. However, before you quote the client in the section, ask for permission. 

Before you move forward into how you helped the client solve their problems, you need to share how they found you. How did the client first make contact with you?

There are a few ways that your client may have found you. They include:

• You may want to share this information if your client found you using a simple Google search.
• If the client found you via a referral from the previous client, you may want to mention that. 
• You could also include if you reached out to the client using a cold call. 

Then, you may want to mention why the client decided to choose you. How did you convince the client to give you a chance to solve the problem? Finally, you may want to share information about your customer service, the strategies you presented, or the project overview you shared. 

Now is the time to get into some of the details. You probably have a lot of products and services that you offer, so you need to explain how you decided to help the client with their problem. What solution did you decide to choose? Why did you decide to go with that solution?

Here is an example of a marketing case study related to an SEO campaign a marketing firm may have constructed. A few portions of this section include:

• “We started by conducting a comprehensive audit of the existing SEO campaign to determine what was working and what was not.”
• “During our detailed analysis, we discovered that the client was paying too much attention to competitive keywords. The client was basing its decision to pursue keyword targets based solely on search volume instead of search competitiveness. The client was competing against national brands that are incredibly difficult to displace from the top of the search engine results page.”
• “We also conducted a detailed target market analysis to determine the optimal target market. That way, we could generate more website traffic and the right type of traffic.”
• “During our analysis, we developed a list of long-tail keywords that were not as competitive and would still provide the right type of traffic.”
• “We A/B tested different content types to determine the most appealing content to search engines and the target market.”
• “We incorporated long-tail keywords into different types of content before posting it on the website.” 

Notice that this detailed strategy clearly explains how it was developed, implemented, and unfolded. This is also an excellent section to include quotes from the client. You may also want to include information on why you chose one strategy over another. This is also an excellent section to include graphs. Some people may not want to read the entire thing, and you can provide them with an excellent visual alternative. Here is a case study example to check out.

After finishing the strategy section, you can showcase the results. This is your time to shine. Make sure to highlight the best case study results, and do not forget to explain why those results are so beneficial. A few examples of results statements you may want to include might be: 

• “Our results showed a 200 percent increase in traffic and a 300 percent increase in conversion rate over six months by interesting a better landing page into the marketing strategy. Because of this increase in website traffic, the client also enjoyed a significant revenue boost.”
• “We implemented a change in the automated menu to shorten the number of time customers spent waiting. As a result, customers were routed to the right location 25 percent faster during the next three months.” 
• “Our results show that the client generated 25 percent more revenue than the same month last year because of the changes we made to the website homepage.” 

Remember that you will probably have multiple results you want to showcase. Make sure to tackle the case study from every direction to provide a well-rounded picture of why your strategy worked well. Here is an example of a case study from a home building company. 

Next, you can wrap up the case study with an excellent conclusion. You can reiterate the main points from the case study, such as the problem, the strategy, and the solution.

You may also want to provide an update on how the client is doing after you parted ways. Is the client still using the strategy you implemented? Is it still working well? This is another good place to use some quotes from your client. For example, if your client appreciates your hard work, include it at the bottom of the case study.

You may also want to mention some other important pieces of advice you shared with the client on your way out the door. The conclusion is also a spot where you can talk about different situations where your best solution or research method might apply. For example, if you helped out a local family medicine practice, you may want to discuss why your strategy might also be helpful for other types of medicine. That way, you can convince people to reach out to you to learn more about this compelling story. Remember that different types of case studies might have different formats.

Before you submit your case study, be sure to proofread your work carefully. You must present a polished, finished product, so you must check for any grammar, spelling, or punctuation errors. You might also want to have a colleague look over your case study for stylistic purposes.

If you are interested in learning more, check out our essay writing tips !

Designing and Conducting Case Studies

This guide examines case studies, a form of qualitative descriptive research that is used to look at individuals, a small group of participants, or a group as a whole. Researchers collect data about participants using participant and direct observations, interviews, protocols, tests, examinations of records, and collections of writing samples. Starting with a definition of the case study, the guide moves to a brief history of this research method. Using several well documented case studies, the guide then looks at applications and methods including data collection and analysis. A discussion of ways to handle validity, reliability, and generalizability follows, with special attention to case studies as they are applied to composition studies. Finally, this guide examines the strengths and weaknesses of case studies.

Definition and Overview

Case study refers to the collection and presentation of detailed information about a particular participant or small group, frequently including the accounts of subjects themselves. A form of qualitative descriptive research, the case study looks intensely at an individual or small participant pool, drawing conclusions only about that participant or group and only in that specific context. Researchers do not focus on the discovery of a universal, generalizable truth, nor do they typically look for cause-effect relationships; instead, emphasis is placed on exploration and description.

Case studies typically examine the interplay of all variables in order to provide as complete an understanding of an event or situation as possible. This type of comprehensive understanding is arrived at through a process known as thick description, which involves an in-depth description of the entity being evaluated, the circumstances under which it is used, the characteristics of the people involved in it, and the nature of the community in which it is located. Thick description also involves interpreting the meaning of demographic and descriptive data such as cultural norms and mores, community values, ingrained attitudes, and motives.

Unlike quantitative methods of research, like the survey, which focus on the questions of who, what, where, how much, and how many, and archival analysis, which often situates the participant in some form of historical context, case studies are the preferred strategy when how or why questions are asked. Likewise, they are the preferred method when the researcher has little control over the events, and when there is a contemporary focus within a real life context. In addition, unlike more specifically directed experiments, case studies require a problem that seeks a holistic understanding of the event or situation in question using inductive logic--reasoning from specific to more general terms.

In scholarly circles, case studies are frequently discussed within the context of qualitative research and naturalistic inquiry. Case studies are often referred to interchangeably with ethnography, field study, and participant observation. The underlying philosophical assumptions in the case are similar to these types of qualitative research because each takes place in a natural setting (such as a classroom, neighborhood, or private home), and strives for a more holistic interpretation of the event or situation under study.

Unlike more statistically-based studies which search for quantifiable data, the goal of a case study is to offer new variables and questions for further research. F.H. Giddings, a sociologist in the early part of the century, compares statistical methods to the case study on the basis that the former are concerned with the distribution of a particular trait, or a small number of traits, in a population, whereas the case study is concerned with the whole variety of traits to be found in a particular instance" (Hammersley 95).

Case studies are not a new form of research; naturalistic inquiry was the primary research tool until the development of the scientific method. The fields of sociology and anthropology are credited with the primary shaping of the concept as we know it today. However, case study research has drawn from a number of other areas as well: the clinical methods of doctors; the casework technique being developed by social workers; the methods of historians and anthropologists, plus the qualitative descriptions provided by quantitative researchers like LePlay; and, in the case of Robert Park, the techniques of newspaper reporters and novelists.

Park was an ex-newspaper reporter and editor who became very influential in developing sociological case studies at the University of Chicago in the 1920s. As a newspaper professional he coined the term "scientific" or "depth" reporting: the description of local events in a way that pointed to major social trends. Park viewed the sociologist as "merely a more accurate, responsible, and scientific reporter." Park stressed the variety and value of human experience. He believed that sociology sought to arrive at natural, but fluid, laws and generalizations in regard to human nature and society. These laws weren't static laws of the kind sought by many positivists and natural law theorists, but rather, they were laws of becoming--with a constant possibility of change. Park encouraged students to get out of the library, to quit looking at papers and books, and to view the constant experiment of human experience. He writes, "Go and sit in the lounges of the luxury hotels and on the doorsteps of the flophouses; sit on the Gold Coast settees and on the slum shakedowns; sit in the Orchestra Hall and in the Star and Garter Burlesque. In short, gentlemen [sic], go get the seats of your pants dirty in real research."

But over the years, case studies have drawn their share of criticism. In fact, the method had its detractors from the start. In the 1920s, the debate between pro-qualitative and pro-quantitative became quite heated. Case studies, when compared to statistics, were considered by many to be unscientific. From the 1930's on, the rise of positivism had a growing influence on quantitative methods in sociology. People wanted static, generalizable laws in science. The sociological positivists were looking for stable laws of social phenomena. They criticized case study research because it failed to provide evidence of inter subjective agreement. Also, they condemned it because of the few number of cases studied and that the under-standardized character of their descriptions made generalization impossible. By the 1950s, quantitative methods, in the form of survey research, had become the dominant sociological approach and case study had become a minority practice.

Educational Applications

The 1950's marked the dawning of a new era in case study research, namely that of the utilization of the case study as a teaching method. "Instituted at Harvard Business School in the 1950s as a primary method of teaching, cases have since been used in classrooms and lecture halls alike, either as part of a course of study or as the main focus of the course to which other teaching material is added" (Armisted 1984). The basic purpose of instituting the case method as a teaching strategy was "to transfer much of the responsibility for learning from the teacher on to the student, whose role, as a result, shifts away from passive absorption toward active construction" (Boehrer 1990). Through careful examination and discussion of various cases, "students learn to identify actual problems, to recognize key players and their agendas, and to become aware of those aspects of the situation that contribute to the problem" (Merseth 1991). In addition, students are encouraged to "generate their own analysis of the problems under consideration, to develop their own solutions, and to practically apply their own knowledge of theory to these problems" (Boyce 1993). Along the way, students also develop "the power to analyze and to master a tangled circumstance by identifying and delineating important factors; the ability to utilize ideas, to test them against facts, and to throw them into fresh combinations" (Merseth 1991).

In addition to the practical application and testing of scholarly knowledge, case discussions can also help students prepare for real-world problems, situations and crises by providing an approximation of various professional environments (i.e. classroom, board room, courtroom, or hospital). Thus, through the examination of specific cases, students are given the opportunity to work out their own professional issues through the trials, tribulations, experiences, and research findings of others. An obvious advantage to this mode of instruction is that it allows students the exposure to settings and contexts that they might not otherwise experience. For example, a student interested in studying the effects of poverty on minority secondary student's grade point averages and S.A.T. scores could access and analyze information from schools as geographically diverse as Los Angeles, New York City, Miami, and New Mexico without ever having to leave the classroom.

The case study method also incorporates the idea that students can learn from one another "by engaging with each other and with each other's ideas, by asserting something and then having it questioned, challenged and thrown back at them so that they can reflect on what they hear, and then refine what they say" (Boehrer 1990). In summary, students can direct their own learning by formulating questions and taking responsibility for the study.

Types and Design Concerns

Researchers use multiple methods and approaches to conduct case studies.

Types of Case Studies

Under the more generalized category of case study exist several subdivisions, each of which is custom selected for use depending upon the goals and/or objectives of the investigator. These types of case study include the following:

Illustrative Case Studies These are primarily descriptive studies. They typically utilize one or two instances of an event to show what a situation is like. Illustrative case studies serve primarily to make the unfamiliar familiar and to give readers a common language about the topic in question.

Exploratory (or pilot) Case Studies These are condensed case studies performed before implementing a large scale investigation. Their basic function is to help identify questions and select types of measurement prior to the main investigation. The primary pitfall of this type of study is that initial findings may seem convincing enough to be released prematurely as conclusions.

Cumulative Case Studies These serve to aggregate information from several sites collected at different times. The idea behind these studies is the collection of past studies will allow for greater generalization without additional cost or time being expended on new, possibly repetitive studies.

Critical Instance Case Studies These examine one or more sites for either the purpose of examining a situation of unique interest with little to no interest in generalizability, or to call into question or challenge a highly generalized or universal assertion. This method is useful for answering cause and effect questions.

Identifying a Theoretical Perspective

Much of the case study's design is inherently determined for researchers, depending on the field from which they are working. In composition studies, researchers are typically working from a qualitative, descriptive standpoint. In contrast, physicists will approach their research from a more quantitative perspective. Still, in designing the study, researchers need to make explicit the questions to be explored and the theoretical perspective from which they will approach the case. The three most commonly adopted theories are listed below:

Individual Theories These focus primarily on the individual development, cognitive behavior, personality, learning and disability, and interpersonal interactions of a particular subject.

Organizational Theories These focus on bureaucracies, institutions, organizational structure and functions, or excellence in organizational performance.

Social Theories These focus on urban development, group behavior, cultural institutions, or marketplace functions.

Two examples of case studies are used consistently throughout this chapter. The first, a study produced by Berkenkotter, Huckin, and Ackerman (1988), looks at a first year graduate student's initiation into an academic writing program. The study uses participant-observer and linguistic data collecting techniques to assess the student's knowledge of appropriate discourse conventions. Using the pseudonym Nate to refer to the subject, the study sought to illuminate the particular experience rather than to generalize about the experience of fledgling academic writers collectively.

For example, in Berkenkotter, Huckin, and Ackerman's (1988) study we are told that the researchers are interested in disciplinary communities. In the first paragraph, they ask what constitutes membership in a disciplinary community and how achieving membership might affect a writer's understanding and production of texts. In the third paragraph they state that researchers must negotiate their claims "within the context of his sub specialty's accepted knowledge and methodology." In the next paragraph they ask, "How is literacy acquired? What is the process through which novices gain community membership? And what factors either aid or hinder students learning the requisite linguistic behaviors?" This introductory section ends with a paragraph in which the study's authors claim that during the course of the study, the subject, Nate, successfully makes the transition from "skilled novice" to become an initiated member of the academic discourse community and that his texts exhibit linguistic changes which indicate this transition. In the next section the authors make explicit the sociolinguistic theoretical and methodological assumptions on which the study is based (1988). Thus the reader has a good understanding of the authors' theoretical background and purpose in conducting the study even before it is explicitly stated on the fourth page of the study. "Our purpose was to examine the effects of the educational context on one graduate student's production of texts as he wrote in different courses and for different faculty members over the academic year 1984-85." The goal of the study then, was to explore the idea that writers must be initiated into a writing community, and that this initiation will change the way one writes.

The second example is Janet Emig's (1971) study of the composing process of a group of twelfth graders. In this study, Emig seeks to answer the question of what happens to the self as a result educational stimuli in terms of academic writing. The case study used methods such as protocol analysis, tape-recorded interviews, and discourse analysis.

In the case of Janet Emig's (1971) study of the composing process of eight twelfth graders, four specific hypotheses were made:

• Twelfth grade writers engage in two modes of composing: reflexive and extensive.
• These differences can be ascertained and characterized through having the writers compose aloud their composition process.
• A set of implied stylistic principles governs the writing process.
• For twelfth grade writers, extensive writing occurs chiefly as a school-sponsored activity, or reflexive, as a self-sponsored activity.

In this study, the chief distinction is between the two dominant modes of composing among older, secondary school students. The distinctions are:

• The reflexive mode, which focuses on the writer's thoughts and feelings.
• The extensive mode, which focuses on conveying a message.

Emig also outlines the specific questions which guided the research in the opening pages of her Review of Literature , preceding the report.

Designing a Case Study

After considering the different sub categories of case study and identifying a theoretical perspective, researchers can begin to design their study. Research design is the string of logic that ultimately links the data to be collected and the conclusions to be drawn to the initial questions of the study. Typically, research designs deal with at least four problems:

• What questions to study
• What data are relevant
• What data to collect
• How to analyze that data

In other words, a research design is basically a blueprint for getting from the beginning to the end of a study. The beginning is an initial set of questions to be answered, and the end is some set of conclusions about those questions.

Because case studies are conducted on topics as diverse as Anglo-Saxon Literature (Thrane 1986) and AIDS prevention (Van Vugt 1994), it is virtually impossible to outline any strict or universal method or design for conducting the case study. However, Robert K. Yin (1993) does offer five basic components of a research design:

• A study's questions.
• A study's propositions (if any).
• A study's units of analysis.
• The logic that links the data to the propositions.
• The criteria for interpreting the findings.

In addition to these five basic components, Yin also stresses the importance of clearly articulating one's theoretical perspective, determining the goals of the study, selecting one's subject(s), selecting the appropriate method(s) of collecting data, and providing some considerations to the composition of the final report.

Conducting Case Studies

To obtain as complete a picture of the participant as possible, case study researchers can employ a variety of approaches and methods. These approaches, methods, and related issues are discussed in depth in this section.

Method: Single or Multi-modal?

To obtain as complete a picture of the participant as possible, case study researchers can employ a variety of methods. Some common methods include interviews , protocol analyses, field studies, and participant-observations. Emig (1971) chose to use several methods of data collection. Her sources included conversations with the students, protocol analysis, discrete observations of actual composition, writing samples from each student, and school records (Lauer and Asher 1988).

Berkenkotter, Huckin, and Ackerman (1988) collected data by observing classrooms, conducting faculty and student interviews, collecting self reports from the subject, and by looking at the subject's written work.

A study that was criticized for using a single method model was done by Flower and Hayes (1984). In this study that explores the ways in which writers use different forms of knowing to create space, the authors used only protocol analysis to gather data. The study came under heavy fire because of their decision to use only one method.

Participant Selection

Case studies can use one participant, or a small group of participants. However, it is important that the participant pool remain relatively small. The participants can represent a diverse cross section of society, but this isn't necessary.

For example, the Berkenkotter, Huckin, and Ackerman (1988) study looked at just one participant, Nate. By contrast, in Janet Emig's (1971) study of the composition process of twelfth graders, eight participants were selected representing a diverse cross section of the community, with volunteers from an all-white upper-middle-class suburban school, an all-black inner-city school, a racially mixed lower-middle-class school, an economically and racially mixed school, and a university school.

Often, a brief "case history" is done on the participants of the study in order to provide researchers with a clearer understanding of their participants, as well as some insight as to how their own personal histories might affect the outcome of the study. For instance, in Emig's study, the investigator had access to the school records of five of the participants, and to standardized test scores for the remaining three. Also made available to the researcher was the information that three of the eight students were selected as NCTE Achievement Award winners. These personal histories can be useful in later stages of the study when data are being analyzed and conclusions drawn.

Data Collection

There are six types of data collected in case studies:

• Archival records.
• Interviews.
• Direct observation.
• Participant observation.

In the field of composition research, these six sources might be:

• A writer's drafts.
• School records of student writers.
• Transcripts of interviews with a writer.
• Transcripts of conversations between writers (and protocols).
• Videotapes and notes from direct field observations.
• Hard copies of a writer's work on computer.

Depending on whether researchers have chosen to use a single or multi-modal approach for the case study, they may choose to collect data from one or any combination of these sources.

Protocols, that is, transcriptions of participants talking aloud about what they are doing as they do it, have been particularly common in composition case studies. For example, in Emig's (1971) study, the students were asked, in four different sessions, to give oral autobiographies of their writing experiences and to compose aloud three themes in the presence of a tape recorder and the investigator.

In some studies, only one method of data collection is conducted. For example, the Flower and Hayes (1981) report on the cognitive process theory of writing depends on protocol analysis alone. However, using multiple sources of evidence to increase the reliability and validity of the data can be advantageous.

Case studies are likely to be much more convincing and accurate if they are based on several different sources of information, following a corroborating mode. This conclusion is echoed among many composition researchers. For example, in her study of predrafting processes of high and low-apprehensive writers, Cynthia Selfe (1985) argues that because "methods of indirect observation provide only an incomplete reflection of the complex set of processes involved in composing, a combination of several such methods should be used to gather data in any one study." Thus, in this study, Selfe collected her data from protocols, observations of students role playing their writing processes, audio taped interviews with the students, and videotaped observations of the students in the process of composing.

It can be said then, that cross checking data from multiple sources can help provide a multidimensional profile of composing activities in a particular setting. Sharan Merriam (1985) suggests "checking, verifying, testing, probing, and confirming collected data as you go, arguing that this process will follow in a funnel-like design resulting in less data gathering in later phases of the study along with a congruent increase in analysis checking, verifying, and confirming."

It is important to note that in case studies, as in any qualitative descriptive research, while researchers begin their studies with one or several questions driving the inquiry (which influence the key factors the researcher will be looking for during data collection), a researcher may find new key factors emerging during data collection. These might be unexpected patterns or linguistic features which become evident only during the course of the research. While not bearing directly on the researcher's guiding questions, these variables may become the basis for new questions asked at the end of the report, thus linking to the possibility of further research.

Data Analysis

As the information is collected, researchers strive to make sense of their data. Generally, researchers interpret their data in one of two ways: holistically or through coding. Holistic analysis does not attempt to break the evidence into parts, but rather to draw conclusions based on the text as a whole. Flower and Hayes (1981), for example, make inferences from entire sections of their students' protocols, rather than searching through the transcripts to look for isolatable characteristics.

However, composition researchers commonly interpret their data by coding, that is by systematically searching data to identify and/or categorize specific observable actions or characteristics. These observable actions then become the key variables in the study. Sharan Merriam (1988) suggests seven analytic frameworks for the organization and presentation of data:

• The role of participants.
• The network analysis of formal and informal exchanges among groups.
• Historical.
• Thematical.
• Ritual and symbolism.
• Critical incidents that challenge or reinforce fundamental beliefs, practices, and values.

There are two purposes of these frameworks: to look for patterns among the data and to look for patterns that give meaning to the case study.

As stated above, while most researchers begin their case studies expecting to look for particular observable characteristics, it is not unusual for key variables to emerge during data collection. Typical variables coded in case studies of writers include pauses writers make in the production of a text, the use of specific linguistic units (such as nouns or verbs), and writing processes (planning, drafting, revising, and editing). In the Berkenkotter, Huckin, and Ackerman (1988) study, for example, researchers coded the participant's texts for use of connectives, discourse demonstratives, average sentence length, off-register words, use of the first person pronoun, and the ratio of definite articles to indefinite articles.

Since coding is inherently subjective, more than one coder is usually employed. In the Berkenkotter, Huckin, and Ackerman (1988) study, for example, three rhetoricians were employed to code the participant's texts for off-register phrases. The researchers established the agreement among the coders before concluding that the participant used fewer off-register words as the graduate program progressed.

Composing the Case Study Report

In the many forms it can take, "a case study is generically a story; it presents the concrete narrative detail of actual, or at least realistic events, it has a plot, exposition, characters, and sometimes even dialogue" (Boehrer 1990). Generally, case study reports are extensively descriptive, with "the most problematic issue often referred to as being the determination of the right combination of description and analysis" (1990). Typically, authors address each step of the research process, and attempt to give the reader as much context as possible for the decisions made in the research design and for the conclusions drawn.

This contextualization usually includes a detailed explanation of the researchers' theoretical positions, of how those theories drove the inquiry or led to the guiding research questions, of the participants' backgrounds, of the processes of data collection, of the training and limitations of the coders, along with a strong attempt to make connections between the data and the conclusions evident.

Although the Berkenkotter, Huckin, and Ackerman (1988) study does not, case study reports often include the reactions of the participants to the study or to the researchers' conclusions. Because case studies tend to be exploratory, most end with implications for further study. Here researchers may identify significant variables that emerged during the research and suggest studies related to these, or the authors may suggest further general questions that their case study generated.

For example, Emig's (1971) study concludes with a section dedicated solely to the topic of implications for further research, in which she suggests several means by which this particular study could have been improved, as well as questions and ideas raised by this study which other researchers might like to address, such as: is there a correlation between a certain personality and a certain composing process profile (e.g. is there a positive correlation between ego strength and persistence in revising)?

Also included in Emig's study is a section dedicated to implications for teaching, which outlines the pedagogical ramifications of the study's findings for teachers currently involved in high school writing programs.

Sharan Merriam (1985) also offers several suggestions for alternative presentations of data:

• Prepare specialized condensations for appropriate groups.
• Replace narrative sections with a series of answers to open-ended questions.
• Present "skimmer's" summaries at beginning of each section.
• Incorporate headlines that encapsulate information from text.
• Prepare analytic summaries with supporting data appendixes.
• Present data in colorful and/or unique graphic representations.

Issues of Validity and Reliability

Once key variables have been identified, they can be analyzed. Reliability becomes a key concern at this stage, and many case study researchers go to great lengths to ensure that their interpretations of the data will be both reliable and valid. Because issues of validity and reliability are an important part of any study in the social sciences, it is important to identify some ways of dealing with results.

Multi-modal case study researchers often balance the results of their coding with data from interviews or writer's reflections upon their own work. Consequently, the researchers' conclusions become highly contextualized. For example, in a case study which looked at the time spent in different stages of the writing process, Berkenkotter concluded that her participant, Donald Murray, spent more time planning his essays than in other writing stages. The report of this case study is followed by Murray's reply, wherein he agrees with some of Berkenkotter's conclusions and disagrees with others.

As is the case with other research methodologies, issues of external validity, construct validity, and reliability need to be carefully considered.

Commentary on Case Studies

Researchers often debate the relative merits of particular methods, among them case study. In this section, we comment on two key issues. To read the commentaries, choose any of the items below:

Strengths and Weaknesses of Case Studies

Most case study advocates point out that case studies produce much more detailed information than what is available through a statistical analysis. Advocates will also hold that while statistical methods might be able to deal with situations where behavior is homogeneous and routine, case studies are needed to deal with creativity, innovation, and context. Detractors argue that case studies are difficult to generalize because of inherent subjectivity and because they are based on qualitative subjective data, generalizable only to a particular context.

Flexibility

The case study approach is a comparatively flexible method of scientific research. Because its project designs seem to emphasize exploration rather than prescription or prediction, researchers are comparatively freer to discover and address issues as they arise in their experiments. In addition, the looser format of case studies allows researchers to begin with broad questions and narrow their focus as their experiment progresses rather than attempt to predict every possible outcome before the experiment is conducted.

Emphasis on Context

By seeking to understand as much as possible about a single subject or small group of subjects, case studies specialize in "deep data," or "thick description"--information based on particular contexts that can give research results a more human face. This emphasis can help bridge the gap between abstract research and concrete practice by allowing researchers to compare their firsthand observations with the quantitative results obtained through other methods of research.

Inherent Subjectivity

"The case study has long been stereotyped as the weak sibling among social science methods," and is often criticized as being too subjective and even pseudo-scientific. Likewise, "investigators who do case studies are often regarded as having deviated from their academic disciplines, and their investigations as having insufficient precision (that is, quantification), objectivity and rigor" (Yin 1989). Opponents cite opportunities for subjectivity in the implementation, presentation, and evaluation of case study research. The approach relies on personal interpretation of data and inferences. Results may not be generalizable, are difficult to test for validity, and rarely offer a problem-solving prescription. Simply put, relying on one or a few subjects as a basis for cognitive extrapolations runs the risk of inferring too much from what might be circumstance.

High Investment

Case studies can involve learning more about the subjects being tested than most researchers would care to know--their educational background, emotional background, perceptions of themselves and their surroundings, their likes, dislikes, and so on. Because of its emphasis on "deep data," the case study is out of reach for many large-scale research projects which look at a subject pool in the tens of thousands. A budget request of $10,000 to examine 200 subjects sounds more efficient than a similar request to examine four subjects.

Ethical Considerations

Researchers conducting case studies should consider certain ethical issues. For example, many educational case studies are often financed by people who have, either directly or indirectly, power over both those being studied and those conducting the investigation (1985). This conflict of interests can hinder the credibility of the study.

The personal integrity, sensitivity, and possible prejudices and/or biases of the investigators need to be taken into consideration as well. Personal biases can creep into how the research is conducted, alternative research methods used, and the preparation of surveys and questionnaires.

A common complaint in case study research is that investigators change direction during the course of the study unaware that their original research design was inadequate for the revised investigation. Thus, the researchers leave unknown gaps and biases in the study. To avoid this, researchers should report preliminary findings so that the likelihood of bias will be reduced.

Concerns about Reliability, Validity, and Generalizability

Merriam (1985) offers several suggestions for how case study researchers might actively combat the popular attacks on the validity, reliability, and generalizability of case studies:

• Prolong the Processes of Data Gathering on Site: This will help to insure the accuracy of the findings by providing the researcher with more concrete information upon which to formulate interpretations.
• Employ the Process of "Triangulation": Use a variety of data sources as opposed to relying solely upon one avenue of observation. One example of such a data check would be what McClintock, Brannon, and Maynard (1985) refer to as a "case cluster method," that is, when a single unit within a larger case is randomly sampled, and that data treated quantitatively." For instance, in Emig's (1971) study, the case cluster method was employed, singling out the productivity of a single student named Lynn. This cluster profile included an advanced case history of the subject, specific examination and analysis of individual compositions and protocols, and extensive interview sessions. The seven remaining students were then compared with the case of Lynn, to ascertain if there are any shared, or unique dimensions to the composing process engaged in by these eight students.
• Conduct Member Checks: Initiate and maintain an active corroboration on the interpretation of data between the researcher and those who provided the data. In other words, talk to your subjects.
• Collect Referential Materials: Complement the file of materials from the actual site with additional document support. For example, Emig (1971) supports her initial propositions with historical accounts by writers such as T.S. Eliot, James Joyce, and D.H. Lawrence. Emig also cites examples of theoretical research done with regards to the creative process, as well as examples of empirical research dealing with the writing of adolescents. Specific attention is then given to the four stages description of the composing process delineated by Helmoltz, Wallas, and Cowley, as it serves as the focal point in this study.
• Engage in Peer Consultation: Prior to composing the final draft of the report, researchers should consult with colleagues in order to establish validity through pooled judgment.

Although little can be done to combat challenges concerning the generalizability of case studies, "most writers suggest that qualitative research should be judged as credible and confirmable as opposed to valid and reliable" (Merriam 1985). Likewise, it has been argued that "rather than transplanting statistical, quantitative notions of generalizability and thus finding qualitative research inadequate, it makes more sense to develop an understanding of generalization that is congruent with the basic characteristics of qualitative inquiry" (1985). After all, criticizing the case study method for being ungeneralizable is comparable to criticizing a washing machine for not being able to tell the correct time. In other words, it is unjust to criticize a method for not being able to do something which it was never originally designed to do in the first place.

Annotated Bibliography

Armisted, C. (1984). How Useful are Case Studies. Training and Development Journal, 38 (2), 75-77.

This article looks at eight types of case studies, offers pros and cons of using case studies in the classroom, and gives suggestions for successfully writing and using case studies.

Bardovi-Harlig, K. (1997). Beyond Methods: Components of Second Language Teacher Education . New York: McGraw-Hill.

A compilation of various research essays which address issues of language teacher education. Essays included are: "Non-native reading research and theory" by Lee, "The case for Psycholinguistics" by VanPatten, and "Assessment and Second Language Teaching" by Gradman and Reed.

Bartlett, L. (1989). A Question of Good Judgment; Interpretation Theory and Qualitative Enquiry Address. 70th Annual Meeting of the American Educational Research Association. San Francisco.

Bartlett selected "quasi-historical" methodology, which focuses on the "truth" found in case records, as one that will provide "good judgments" in educational inquiry. He argues that although the method is not comprehensive, it can try to connect theory with practice.

Baydere, S. et. al. (1993). Multimedia conferencing as a tool for collaborative writing: a case study in Computer Supported Collaborative Writing. New York: Springer-Verlag.

The case study by Baydere et. al. is just one of the many essays in this book found in the series "Computer Supported Cooperative Work." Denley, Witefield and May explore similar issues in their essay, "A case study in task analysis for the design of a collaborative document production system."

Berkenkotter, C., Huckin, T., N., & Ackerman J. (1988). Conventions, Conversations, and the Writer: Case Study of a Student in a Rhetoric Ph.D. Program. Research in the Teaching of English, 22, 9-44.

The authors focused on how the writing of their subject, Nate or Ackerman, changed as he became more acquainted or familiar with his field's discourse community.

Berninger, V., W., and Gans, B., M. (1986). Language Profiles in Nonspeaking Individuals of Normal Intelligence with Severe Cerebral Palsy. Augmentative and Alternative Communication, 2, 45-50.

Argues that generalizations about language abilities in patients with severe cerebral palsy (CP) should be avoided. Standardized tests of different levels of processing oral language, of processing written language, and of producing written language were administered to 3 male participants (aged 9, 16, and 40 yrs).

Bockman, J., R., and Couture, B. (1984). The Case Method in Technical Communication: Theory and Models. Texas: Association of Teachers of Technical Writing.

Examines the study and teaching of technical writing, communication of technical information, and the case method in terms of those applications.

Boehrer, J. (1990). Teaching With Cases: Learning to Question. New Directions for Teaching and Learning, 42 41-57.

This article discusses the origins of the case method, looks at the question of what is a case, gives ideas about learning in case teaching, the purposes it can serve in the classroom, the ground rules for the case discussion, including the role of the question, and new directions for case teaching.

Bowman, W. R. (1993). Evaluating JTPA Programs for Economically Disadvantaged Adults: A Case Study of Utah and General Findings . Washington: National Commission for Employment Policy.

"To encourage state-level evaluations of JTPA, the Commission and the State of Utah co-sponsored this report on the effectiveness of JTPA Title II programs for adults in Utah. The technique used is non-experimental and the comparison group was selected from registrants with Utah's Employment Security. In a step-by-step approach, the report documents how non-experimental techniques can be applied and several specific technical issues can be addressed."

Boyce, A. (1993) The Case Study Approach for Pedagogists. Annual Meeting of the American Alliance for Health, Physical Education, Recreation and Dance. (Address). Washington DC.

This paper addresses how case studies 1) bridge the gap between teaching theory and application, 2) enable students to analyze problems and develop solutions for situations that will be encountered in the real world of teaching, and 3) helps students to evaluate the feasibility of alternatives and to understand the ramifications of a particular course of action.

Carson, J. (1993) The Case Study: Ideal Home of WAC Quantitative and Qualitative Data. Annual Meeting of the Conference on College Composition and Communication. (Address). San Diego.

"Increasingly, one of the most pressing questions for WAC advocates is how to keep [WAC] programs going in the face of numerous difficulties. Case histories offer the best chance for fashioning rhetorical arguments to keep WAC programs going because they offer the opportunity to provide a coherent narrative that contextualizes all documents and data, including what is generally considered scientific data. A case study of the WAC program, . . . at Robert Morris College in Pittsburgh demonstrates the advantages of this research method. Such studies are ideal homes for both naturalistic and positivistic data as well as both quantitative and qualitative information."

---. (1991). A Cognitive Process Theory of Writing. College Composition and Communication. 32. 365-87.

No abstract available.

Cromer, R. (1994) A Case Study of Dissociations Between Language and Cognition. Constraints on Language Acquisition: Studies of Atypical Children . Hillsdale: Lawrence Erlbaum Associates, 141-153.

Crossley, M. (1983) Case Study in Comparative and International Education: An Approach to Bridging the Theory-Practice Gap. Proceedings of the 11th Annual Conference of the Australian Comparative and International Education Society. Hamilton, NZ.

Case study research, as presented here, helps bridge the theory-practice gap in comparative and international research studies of education because it focuses on the practical, day-to-day context rather than on the national arena. The paper asserts that the case study method can be valuable at all levels of research, formation, and verification of theories in education.

Daillak, R., H., and Alkin, M., C. (1982). Qualitative Studies in Context: Reflections on the CSE Studies of Evaluation Use . California: EDRS

The report shows how the Center of the Study of Evaluation (CSE) applied qualitative techniques to a study of evaluation information use in local, Los Angeles schools. It critiques the effectiveness and the limitations of using case study, evaluation, field study, and user interview survey methodologies.

Davey, L. (1991). The Application of Case Study Evaluations. ERIC/TM Digest.

This article examines six types of case studies, the type of evaluation questions that can be answered, the functions served, some design features, and some pitfalls of the method.

Deutch, C. E. (1996). A course in research ethics for graduate students. College Teaching, 44, 2, 56-60.

This article describes a one-credit discussion course in research ethics for graduate students in biology. Case studies are focused on within the four parts of the course: 1) major issues, 2 )practical issues in scholarly work, 3) ownership of research results, and 4) training and personal decisions.

DeVoss, G. (1981). Ethics in Fieldwork Research. RIE 27p. (ERIC)

This article examines four of the ethical problems that can happen when conducting case study research: acquiring permission to do research, knowing when to stop digging, the pitfalls of doing collaborative research, and preserving the integrity of the participants.

Driscoll, A. (1985). Case Study of a Research Intervention: the University of Utah’s Collaborative Approach . San Francisco: Far West Library for Educational Research Development.

Paper presented at the annual meeting of the American Association of Colleges of Teacher Education, Denver, CO, March 1985. Offers information of in-service training, specifically case studies application.

Ellram, L. M. (1996). The Use of the Case Study Method in Logistics Research. Journal of Business Logistics, 17, 2, 93.

This article discusses the increased use of case study in business research, and the lack of understanding of when and how to use case study methodology in business.

Emig, J. (1971) The Composing Processes of Twelfth Graders . Urbana: NTCE.

This case study uses observation, tape recordings, writing samples, and school records to show that writing in reflexive and extensive situations caused different lengths of discourse and different clusterings of the components of the writing process.

Feagin, J. R. (1991). A Case For the Case Study . Chapel Hill: The University of North Carolina Press.

This book discusses the nature, characteristics, and basic methodological issues of the case study as a research method.

Feldman, H., Holland, A., & Keefe, K. (1989) Language Abilities after Left Hemisphere Brain Injury: A Case Study of Twins. Topics in Early Childhood Special Education, 9, 32-47.

"Describes the language abilities of 2 twin pairs in which 1 twin (the experimental) suffered brain injury to the left cerebral hemisphere around the time of birth and1 twin (the control) did not. One pair of twins was initially assessed at age 23 mo. and the other at about 30 mo.; they were subsequently evaluated in their homes 3 times at about 6-mo intervals."

Fidel, R. (1984). The Case Study Method: A Case Study. Library and Information Science Research, 6.

The article describes the use of case study methodology to systematically develop a model of online searching behavior in which study design is flexible, subject manner determines data gathering and analyses, and procedures adapt to the study's progressive change.

Flower, L., & Hayes, J. R. (1984). Images, Plans and Prose: The Representation of Meaning in Writing. Written Communication, 1, 120-160.

Explores the ways in which writers actually use different forms of knowing to create prose.

Frey, L. R. (1992). Interpreting Communication Research: A Case Study Approach Englewood Cliffs, N.J.: Prentice Hall.

The book discusses research methodologies in the Communication field. It focuses on how case studies bridge the gap between communication research, theory, and practice.

Gilbert, V. K. (1981). The Case Study as a Research Methodology: Difficulties and Advantages of Integrating the Positivistic, Phenomenological and Grounded Theory Approaches . The Annual Meeting of the Canadian Association for the Study of Educational Administration. (Address) Halifax, NS, Can.

This study on an innovative secondary school in England shows how a "low-profile" participant-observer case study was crucial to the initial observation, the testing of hypotheses, the interpretive approach, and the grounded theory.

Gilgun, J. F. (1994). A Case for Case Studies in Social Work Research. Social Work, 39, 4, 371-381.

This article defines case study research, presents guidelines for evaluation of case studies, and shows the relevance of case studies to social work research. It also looks at issues such as evaluation and interpretations of case studies.

Glennan, S. L., Sharp-Bittner, M. A. & Tullos, D. C. (1991). Augmentative and Alternative Communication Training with a Nonspeaking Adult: Lessons from MH. Augmentative and Alternative Communication, 7, 240-7.

"A response-guided case study documented changes in a nonspeaking 36-yr-old man's ability to communicate using 3 trained augmentative communication modes. . . . Data were collected in videotaped interaction sessions between the nonspeaking adult and a series of adult speaking."

Graves, D. (1981). An Examination of the Writing Processes of Seven Year Old Children. Research in the Teaching of English, 15, 113-134.

Hamel, J. (1993). Case Study Methods . Newbury Park: Sage. .

"In a most economical fashion, Hamel provides a practical guide for producing theoretically sharp and empirically sound sociological case studies. A central idea put forth by Hamel is that case studies must "locate the global in the local" thus making the careful selection of the research site the most critical decision in the analytic process."

Karthigesu, R. (1986, July). Television as a Tool for Nation-Building in the Third World: A Post-Colonial Pattern, Using Malaysia as a Case-Study. International Television Studies Conference. (Address). London, 10-12.

"The extent to which Television Malaysia, as a national mass media organization, has been able to play a role in nation building in the post-colonial period is . . . studied in two parts: how the choice of a model of nation building determines the character of the organization; and how the character of the organization influences the output of the organization."

Kenny, R. (1984). Making the Case for the Case Study. Journal of Curriculum Studies, 16, (1), 37-51.

The article looks at how and why the case study is justified as a viable and valuable approach to educational research and program evaluation.

Knirk, F. (1991). Case Materials: Research and Practice. Performance Improvement Quarterly, 4 (1 ), 73-81.

The article addresses the effectiveness of case studies, subject areas where case studies are commonly used, recent examples of their use, and case study design considerations.

Klos, D. (1976). Students as Case Writers. Teaching of Psychology, 3.2, 63-66.

This article reviews a course in which students gather data for an original case study of another person. The task requires the students to design the study, collect the data, write the narrative, and interpret the findings.

Leftwich, A. (1981). The Politics of Case Study: Problems of Innovation in University Education. Higher Education Review, 13.2, 38-64.

The article discusses the use of case studies as a teaching method. Emphasis is on the instructional materials, interdisciplinarity, and the complex relationships within the university that help or hinder the method.

Mabrito, M. (1991, Oct.). Electronic Mail as a Vehicle for Peer Response: Conversations of High and Low Apprehensive Writers. Written Communication, 509-32.

McCarthy, S., J. (1955). The Influence of Classroom Discourse on Student Texts: The Case of Ella . East Lansing: Institute for Research on Teaching.

A look at how students of color become marginalized within traditional classroom discourse. The essay follows the struggles of one black student: Ella.

Matsuhashi, A., ed. (1987). Writing in Real Time: Modeling Production Processes Norwood, NJ: Ablex Publishing Corporation.

Investigates how writers plan to produce discourse for different purposes to report, to generalize, and to persuade, as well as how writers plan for sentence level units of language. To learn about planning, an observational measure of pause time was used" (ERIC).

Merriam, S. B. (1985). The Case Study in Educational Research: A Review of Selected Literature. Journal of Educational Thought, 19.3, 204-17.

The article examines the characteristics of, philosophical assumptions underlying the case study, the mechanics of conducting a case study, and the concerns about the reliability, validity, and generalizability of the method.

---. (1988). Case Study Research in Education: A Qualitative Approach San Francisco: Jossey Bass.

Merry, S. E., & Milner, N. eds. (1993). The Possibility of Popular Justice: A Case Study of Community Mediation in the United States . Ann Arbor: U of Michigan.

". . . this volume presents a case study of one experiment in popular justice, the San Francisco Community Boards. This program has made an explicit claim to create an alternative justice, or new justice, in the midst of a society ordered by state law. The contributors to this volume explore the history and experience of the program and compare it to other versions of popular justice in the United States, Europe, and the Third World."

Merseth, K. K. (1991). The Case for Cases in Teacher Education. RIE. 42p. (ERIC).

This monograph argues that the case method of instruction offers unique potential for revitalizing the field of teacher education.

Michaels, S. (1987). Text and Context: A New Approach to the Study of Classroom Writing. Discourse Processes, 10, 321-346.

"This paper argues for and illustrates an approach to the study of writing that integrates ethnographic analysis of classroom interaction with linguistic analysis of written texts and teacher/student conversational exchanges. The approach is illustrated through a case study of writing in a single sixth grade classroom during a single writing assignment."

Milburn, G. (1995). Deciphering a Code or Unraveling a Riddle: A Case Study in the Application of a Humanistic Metaphor to the Reporting of Social Studies Teaching. Theory and Research in Education, 13.

This citation serves as an example of how case studies document learning procedures in a senior-level economics course.

Milley, J. E. (1979). An Investigation of Case Study as an Approach to Program Evaluation. 19th Annual Forum of the Association for Institutional Research. (Address). San Diego.

The case study method merged a narrative report focusing on the evaluator as participant-observer with document review, interview, content analysis, attitude questionnaire survey, and sociogram analysis. Milley argues that case study program evaluation has great potential for widespread use.

Minnis, J. R. (1985, Sept.). Ethnography, Case Study, Grounded Theory, and Distance Education Research. Distance Education, 6.2.

This article describes and defines the strengths and weaknesses of ethnography, case study, and grounded theory.

Nunan, D. (1992). Collaborative language learning and teaching . New York: Cambridge University Press.

Included in this series of essays is Peter Sturman’s "Team Teaching: a case study from Japan" and David Nunan’s own "Toward a collaborative approach to curriculum development: a case study."

Nystrand, M., ed. (1982). What Writers Know: The Language, Process, and Structure of Written Discourse . New York: Academic Press.

Owenby, P. H. (1992). Making Case Studies Come Alive. Training, 29, (1), 43-46. (ERIC)

This article provides tips for writing more effective case studies.

---. (1981). Pausing and Planning: The Tempo of Writer Discourse Production. Research in the Teaching of English, 15 (2),113-34.

Perl, S. (1979). The Composing Processes of Unskilled College Writers. Research in the Teaching of English, 13, 317-336.

"Summarizes a study of five unskilled college writers, focusing especially on one of the five, and discusses the findings in light of current pedagogical practice and research design."

Pilcher J. and A. Coffey. eds. (1996). Gender and Qualitative Research . Brookfield: Aldershot, Hants, England.

This book provides a series of essays which look at gender identity research, qualitative research and applications of case study to questions of gendered pedagogy.

Pirie, B. S. (1993). The Case of Morty: A Four Year Study. Gifted Education International, 9 (2), 105-109.

This case study describes a boy from kindergarten through third grade with above average intelligence but difficulty in learning to read, write, and spell.

Popkewitz, T. (1993). Changing Patterns of Power: Social Regulation and Teacher Education Reform. Albany: SUNY Press.

Popkewitz edits this series of essays that address case studies on educational change and the training of teachers. The essays vary in terms of discipline and scope. Also, several authors include case studies of educational practices in countries other than the United States.

---. (1984). The Predrafting Processes of Four High- and Four Low Apprehensive Writers. Research in the Teaching of English, 18, (1), 45-64.

Rasmussen, P. (1985, March) A Case Study on the Evaluation of Research at the Technical University of Denmark. International Journal of Institutional Management in Higher Education, 9 (1).

This is an example of a case study methodology used to evaluate the chemistry and chemical engineering departments at the University of Denmark.

Roth, K. J. (1986). Curriculum Materials, Teacher Talk, and Student Learning: Case Studies in Fifth-Grade Science Teaching . East Lansing: Institute for Research on Teaching.

Roth offers case studies on elementary teachers, elementary school teaching, science studies and teaching, and verbal learning.

Selfe, C. L. (1985). An Apprehensive Writer Composes. When a Writer Can't Write: Studies in Writer's Block and Other Composing-Process Problems . (pp. 83-95). Ed. Mike Rose. NMY: Guilford.

Smith-Lewis, M., R. and Ford, A. (1987). A User's Perspective on Augmentative Communication. Augmentative and Alternative Communication, 3, 12-7.

"During a series of in-depth interviews, a 25-yr-old woman with cerebral palsy who utilized augmentative communication reflected on the effectiveness of the devices designed for her during her school career."

St. Pierre, R., G. (1980, April). Follow Through: A Case Study in Metaevaluation Research . 64th Annual Meeting of the American Educational Research Association. (Address).

The three approaches to metaevaluation are evaluation of primary evaluations, integrative meta-analysis with combined primary evaluation results, and re-analysis of the raw data from a primary evaluation.

Stahler, T., M. (1996, Feb.) Early Field Experiences: A Model That Worked. ERIC.

"This case study of a field and theory class examines a model designed to provide meaningful field experiences for preservice teachers while remaining consistent with the instructor's beliefs about the role of teacher education in preparing teachers for the classroom."

Stake, R. E. (1995). The Art of Case Study Research. Thousand Oaks: Sage Publications.

This book examines case study research in education and case study methodology.

Stiegelbauer, S. (1984) Community, Context, and Co-curriculum: Situational Factors Influencing School Improvements in a Study of High Schools. Presented at the annual meeting of the American Educational Research Association, New Orleans, LA.

Discussion of several case studies: one looking at high school environments, another examining educational innovations.

Stolovitch, H. (1990). Case Study Method. Performance And Instruction, 29, (9), 35-37.

This article describes the case study method as a form of simulation and presents guidelines for their use in professional training situations.

Thaller, E. (1994). Bibliography for the Case Method: Using Case Studies in Teacher Education. RIE. 37 p.

This bibliography presents approximately 450 citations on the use of case studies in teacher education from 1921-1993.

Thrane, T. (1986). On Delimiting the Senses of Near-Synonyms in Historical Semantics: A Case Study of Adjectives of 'Moral Sufficiency' in the Old English Andreas. Linguistics Across Historical and Geographical Boundaries: In Honor of Jacek Fisiak on the Occasion of his Fiftieth Birthday . Berlin: Mouton de Gruyter.

United Nations. (1975). Food and Agriculture Organization. Report on the FAO/UNFPA Seminar on Methodology, Research and Country: Case Studies on Population, Employment and Productivity . Rome: United Nations.

This example case study shows how the methodology can be used in a demographic and psychographic evaluation. At the same time, it discusses the formation and instigation of the case study methodology itself.

Van Vugt, J. P., ed. (1994). Aids Prevention and Services: Community Based Research . Westport: Bergin and Garvey.

"This volume has been five years in the making. In the process, some of the policy applications called for have met with limited success, such as free needle exchange programs in a limited number of American cities, providing condoms to prison inmates, and advertisements that depict same-sex couples. Rather than dating our chapters that deal with such subjects, such policy applications are verifications of the type of research demonstrated here. Furthermore, they indicate the critical need to continue community based research in the various communities threatened by acquired immuno-deficiency syndrome (AIDS) . . . "

Welch, W., ed. (1981, May). Case Study Methodology in Educational Evaluation. Proceedings of the Minnesota Evaluation Conference. Minnesota. (Address).

The four papers in these proceedings provide a comprehensive picture of the rationale, methodology, strengths, and limitations of case studies.

Williams, G. (1987). The Case Method: An Approach to Teaching and Learning in Educational Administration. RIE, 31p.

This paper examines the viability of the case method as a teaching and learning strategy in instructional systems geared toward the training of personnel of the administration of various aspects of educational systems.

Yin, R. K. (1993). Advancing Rigorous Methodologies: A Review of 'Towards Rigor in Reviews of Multivocal Literatures.' Review of Educational Research, 61, (3).

"R. T. Ogawa and B. Malen's article does not meet its own recommended standards for rigorous testing and presentation of its own conclusions. Use of the exploratory case study to analyze multivocal literatures is not supported, and the claim of grounded theory to analyze multivocal literatures may be stronger."

---. (1989). Case Study Research: Design and Methods. London: Sage Publications Inc.

This book discusses in great detail, the entire design process of the case study, including entire chapters on collecting evidence, analyzing evidence, composing the case study report, and designing single and multiple case studies.

Related Links

Consider the following list of related Web sites for more information on the topic of case study research. Note: although many of the links cover the general category of qualitative research, all have sections that address issues of case studies.

• Sage Publications on Qualitative Methodology: Search here for a comprehensive list of new books being published about "Qualitative Methodology" http://www.sagepub.co.uk/
• The International Journal of Qualitative Studies in Education: An on-line journal "to enhance the theory and practice of qualitative research in education." On-line submissions are welcome. http://www.tandf.co.uk/journals/tf/09518398.html
• Qualitative Research Resources on the Internet: From syllabi to home pages to bibliographies. All links relate somehow to qualitative research. http://www.nova.edu/ssss/QR/qualres.html

Becker, Bronwyn, Patrick Dawson, Karen Devine, Carla Hannum, Steve Hill, Jon Leydens, Debbie Matuskevich, Carol Traver, & Mike Palmquist. (2005). Case Studies. Writing@CSU . Colorado State University. https://writing.colostate.edu/guides/guide.cfm?guideid=60

How to Write a Case Study – An Easy Step by Step Guide

As freelance writers, we are always on the lookout for ways to generate more profit and higher rates from our writing services, right?

Adding services, like learning how to write a case case study, can be highly profitable and can help to advance your skills as a web writer.

If you aren’t too familiar with them, writing case studies help businesses tell a story about how they’ve helped their customers reach their goals and how their products or services add value to their customers’ bottom line.

However, learning how to write a case study is different than other forms of content marketing that businesses might use, such as white papers or blog posts.

It’s not an ebook or even a general article.

So, what is a case study and how do you effectively write a case study?

Whether you’re a new or experienced online writer looking to expand your services, I want to share with you how to successfully write case studies that will wow your clients.

In this post, I will share with you what a case study is, how to research for a case study, how to write a case study, give you some case study examples, and even share my tried and true template for formatting my case studies.

You don’t have to be an expert case study writer to offer this as a service to your clients either.

If you want to try your hand at case studies, you can add to your portfolio and even write one for yourself and focus on how you’ve helped your clients with their goals.

I’ve had many of my course students write a case study for clients when they had never written one before.

Adding case studies to their services has helped them to get high-paying projects as a new writer.

Even if you are an experienced writer, it’s always beneficial to get some extra help when taking on a new type of writing service.

So, let’s dive into how to write a case study when you’re new to all of this!

Case Study Definition

Diving into a case study analysis, you’ll notice that case studies offer real-life examples of how your client was able to take their customers from point A to point B. Similar to white papers, case studies use cold, hard statistics. Case studies are also research-driven and require setting up interviews and developing interview questions.

One thing you should know right away is that writing case studies require a little more research and time-intensive hours than other forms of writing.

Not only are you gathering analytics and interviewing clients or customers, but you’re also telling a story.

You have to be able to mesh together the numbers and the emotion of the case study to create a written work that will become a powerful piece of advertising for your client.

If you’re new to this style of writing, it’s easy to see how a case study can be confused with white papers as both are research-driven. However, there are two very large differences that make case studies unique.

The first is case studies are more interview-driven about a successful strategy while white papers are more written like a report about a new feature from a business.

The second part is the story behind how your client was able to provide their customers with value that brought them results.

Even if your client is meticulously tracking their customers’ before and after results, you have to get the story behind that information to write an informative and highly valuable case study. One of the biggest advantages of offering case studies as a service is that you can charge a lot more for them.

A typical case study are anywhere between $500 to $1500 and more.

Finally, most case studies are short-for, research problem focussed content. Case studies, unlike white papers, are often much shorter but the information gathering process can be just as time-intensive.

Case studies, therefore, only span a few pages and are usually under 1500 words.

Case Study Examples

For some, learning how to write a business case study  requires looking at examples of what a great case study looks like.

So, what is an example of a case study?

Companies often use a case study as a way to market their services to a potential customer. It helps to showcase how they’re able to solve their customers’ problems and bring them value – kind of like a testimonial – only with way more information!

For example, Drift uses the case studies to highlight how they’re helping their customers book new business and increase leads through the use of real-time messaging chatbots.

Here’s a case study from Drift that focuses on how they helped Aventri book $1.7 million in new sales in just five months!

Or this case study on how Groupon used Sprinklr to increase their customer response time by responding to 76% of their customer messages within 30 minutes.

Any kind of business can use a case study to highlight a client’s success story.

If the business can get testimonials, it can have a marketing case study written. Like Clio, a legal practice management and client intake software increased their chat leads by 625% with Drift within five months for their global sales team.

Drift and Sprinklr, as well as thousands of other businesses like Wishpond and Creative Industries , use case studies to highlight how their products have helped their customers’ businesses, which in turn, helps to get new customers interested in their products or services.

While many businesses use case studies in a B2B format, businesses can also use case studies to market directly to customers.

As well, case studies can also be podcasts, testimonials, or blog posts like this one for the Allergy Kit.

Case Study Template

Now that you know what a case study is, let’s break down exactly what you should put into an effective case study to help your clients bring in more business. Here is a simple case study template that I follow that you can use to get started writing your first case study.

1.   Introduction

The introduction of your case study should always talk about your client. You can mention their brand, their industry, their services, and any other relevant information.

Then, you can make sure to share some important details that highlight what makes them different – their unique selling point.

You can also briefly mention the problem that the customer faced that relates to the solution that the client was able to provide, without going into too much detail. This is what I did in my mock case study example.

2.   Their Challenges

In this section, talk about the key problem, challenges, or any pain points that the customer was facing that the prospective client wanted you to address (you learn about this in the interview process).

Go much more in-depth about the customer’s problem in this section of your case study.

• How did this problem develop?
• Was it a pre-existing issue or something new?
• Was this problem due to changes in their market or other unforeseen circumstances?

Also talk about what the customer’s initial goals were for working with the client, and how they expected to have their problem solved; this will lead to part four of the case study.

Lastly, why did the customer choose to work with my client specifically? A case study interview might proof to help you with this aspect of writing a case study.

This is great information to have as it will help to further build the client’s social proof.

3.   The Solution

The solution part of the case study is where you can propose the solution and mention all the great things that you client did to help their customers achieve amazing results. Include specific strategies that worked or did not.

• Did the client offer a tried and true method to solve the issue or did they do something new?
• What parts of the client’s team were involved and how did they contribute?
• What was the end solution, what did it look like?
• How did the client use their products or services to solve their customer’s issues?
• What was the timeline involved in delivering the solution to the customer?

Try to only focus on the things that potential customers will care about and don’t worry about including things they will not.

I always make sure to tailor my writing to appeal to the particular avatar that the client is marketing to (you find this out in the interview process as well).

4.   The Results

This is where you can include stats about the progress with supporting evidence. Discuss how the client solved their customers’ issues or accomplished the objectives they set out to achieve.

This is the part that ties back into section #2, their challenges.

If you collected or made any fancy charts or graphs, include them in the results section. Make sure to also focus on the benefits that the client’s customers received that go beyond any of the stats listed.

If this is a case study that covers a longer period of time, I like to include both immediate and long term benefits that the customers have experienced.

In talking about the various stats, try and highlight one as the most important and talk about why that is.

Finally, focus on the relationship between the client and their customer and how the customer now feels about their ROI. Was it worth it? Would they hire the client again?

How Do You Write a Case Study?

Now that you saw a basic case study template, let’s dive into how to write a case study for your clients.

How do you write a case study when you a new to this type of case study writing?

Writing case studies includes three parties, you (the writer), the company you are writing the case study for (client), and who the case study is being written about (customer).

The steps to actually writing a case study are not much different than any other form of writing.

It includes research from your client and their customers and the writing itself, being a bit less formal than a white paper.

Finally, you need to know how to format your case study and how to go about gathering all of the information that you need.

Here are some things to consider when writing your case study:

• Your client’s ideal customer (their avatar)
• The case study format
• Researching the company
• Interviewing clients and customers
• Putting together the numbers and emotion

Your Client’s Ideal Customer

While you find this out during the interviewing process, it’s worth noting here.

Before you write your first word, you need to know who your client’s ideal customer is , who they are specifically trying to market to. While some companies might only offer one service that they target one specific customer, others might have multiple.

You need to know who you’re talking to before you start talking.

How to Format a Case Study

There are several different ways you can format a case study.

A case study can be used as a lead magnet or a blog post. They can even be repurposed and turned into sharable infographics or brochures.

You can write your case study on whatever writing platform you’re most comfortable with, such as Google Docs or Microsoft Word.

If you’re looking for a formatted case study that can really catch a customer’s eye, Venngage has some really colorful and beautiful case study templates.

Make sure that you’re clarifying with the client beforehand exactly what they’re looking for and what their expectations are.

Technically speaking, it’s not your job as the writer to format the case study.

However, if you’re confident in your design skills you can offer that service as an add-on. You can also easily create beautifully formatted case studies in free programs like Canva, PicMonkey and even Google Docs (that’s what I used for my mock up case study template).

How to Research for a Case Study

Make sure you know enough about the company before you write a case study for them.

You should at least know about their history, what products and services they offer, and what value they bring their customers. It’s helpful to interview someone from the client’s company that’s familiar with marketing so they can give you some insight into how their services are marketed.

You need to know how they’re planning on using the case study in their marketing to really make it effective.

For example, a case study that will be a blog post might be different than a case study that will be a lead magnet.

Interviewing Clients and Customers

You should have two main points of contact for interviews. One from your client and one from their customer base.

As mentioned before, the client you interview should have knowledge of the marketing aspect of the business.

This will help to make sure that what you’re writing about is in line with their marketing goals.

The customer you interview should, first of all, know the goal of the interview and be able to give you the information and stats you’re looking for.

They should also be able to tell you their story and how the client’s service or product benefitted them and added value to their business and to their bottom line.

The actual interview itself can take place over Skype or video chat, on the phone, or if necessary through email.

Although, I would suggest actually talking to people – rather than email – as there might be more questions and further insight that comes up during the conversation.

Putting it All Together

This is where you flex your copywriting skills. Compile all of your data and present it in a way that is engaging to the reader.

You don’t want a boring list of statistics that are going to put your reader to sleep.

This is the part of the case study where the story really comes together and focuses on how your client was able to deliver amazing results to their customers.

You can also format the case study during this time as well.

Writing Case Study Questions

Do you have some questions about writing case studies? Let’s look at the most common questions.

How long do writing case studies take?

It depends on who you are interviewing. If you can reach the company or person quickly, it can take a few weeks to a month to compile the information and write the case study.

However, for some interviews, it can take months before you solidify a date for an interview.

What is the typical length of a case study?

Most case studies are short and no more than 1500 words.

What should a case study include?

The most important things a case study should include is the problem and how the company being profiled helped solved the problem. Case studies are success stories, so laying out the problem is key to understanding if the process was successful.

What/how should you quote pricing for case studies?

My recommendation is to either price each case study individually or to have a starting rate of $300-$500. One thing to note is that case study writing isn’t usually recurring, so adding additional services to your freelance writing business is important.

How to Market Case Study Writing to Businesses

Okay. Let’s look at how you can market yourself as a case study writer.

1. Build a Case Study Portfolio

To show potential clients proof that you can write a case study, have writing samples in your portfolio to support this.

It can be as easy as a mock up – like the one I crated for this post – to guest posting about the importance of white papers for businesses.

2. Niche Yourself as a Case Study Writer

It’s a good idea to title yourself as a case study writer, if you primarily want to write case studies. For example, Bonnie mentions her case study writing as the first thing on her services page.

She does a great job by also providing:

• A case study testimonial
• Case study writing samples
• A case study checklist for people who want to DIY it
• Tips to writing a case study (which are more writing samples for her)

It’s also a good idea to title yourself as a case study writer on social media too!

3. Provide Informational Guest Posts on Case Studies

A great marketing strategy to use is to guest post on topics that relate to how case studies can help businesses with their bottom line.

Find blogs that your ideal client reads or visit business blogs that accept guest posts and guest post those types of topics!

Writing a Case Study

There ya go!

How to write a case study with some case study examples and more!

I hope you find this helpful and start pitching to businesses as a case study writer!

For more posts like this, look at my How to Write Series:

• How to Write a White Paper – A Simple Step by Step Guide
• How to Write a Writing Sample for a Job
• How to Write an About Me Page as a Freelance Writer
• How Writing a Cover Letter Can Help You Land That Job
• How to Write an Email as as Copywriter

Over to you – tell me if case studies is something you will offer now!

Share this post with your friends!

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ChatGPT for Teachers

Trauma-informed practices in schools, teacher well-being, cultivating diversity, equity, & inclusion, integrating technology in the classroom, social-emotional development, covid-19 resources, invest in resilience: summer toolkit, civics & resilience, all toolkits, degree programs, trauma-informed professional development, teacher licensure & certification, how to become - career information, classroom management, instructional design, lifestyle & self-care, online higher ed teaching, current events, how to write a case study: the basics.

The purpose of a case study is to walk the reader through a situation where a problem is presented, background information provided and a description of the solution given, along with how it was derived. A case study can be written to encourage the reader to come up with his or her own solution or to review the solution that was already implemented. The goal of the writer is to give the reader experiences similar to those the writer had as he or she researched the situation presented.

Several steps must be taken before actually writing anything:

• Choose the situation on which to write
• Gather as much information as possible about the situation
• Analyze all of the elements surrounding the situation
• Determine the final solution implemented
• Gather information about why the solution worked or did not work

From these steps you will create the content of your case study.

Describe the situation/problem

The reader needs to have a clear understanding of the situation for which a solution is sought. You can explicitly state the problem posed in the study. You can begin by sharing quotes from someone intimate with the situation. Or you can present a question:

• ABC Hospital has a higher post-surgical infection rate than other health care facilities in the area.
• The Director of Nursing at ABC Hospital stated that “In spite of following rigid standards, we continue to experience high post-surgical infection rates”
• Why is it that the post-surgical infection rate at ABC Hospital  higher than any other health center in the area?

This sets the tone for the reader to think of the problem while he or she read the rest of the case study. This also sets the expectation that you will be presenting information the reader can use to further understand the situation.

Give background

Background is the information you discovered that describes why there is a problem. This will consist of facts and figures from authoritative sources. Graphs, charts, tables, photos, videos, audio files, and anything that points to the problem is useful here. Quotes from interviews are also good. You might include anecdotal information as well:

“According to previous employees of this facility, this has been a problem for several years”

What is not included in this section is the author’s opinion:

“I don’t think the infection review procedures are followed very closely”

In this section you give the reader information that they can use to come to their own conclusion. Like writing a mystery, you are giving clues from which the reader can decide how to solve the puzzle. From all of this evidence, how did the problem become a problem? How can the trend be reversed so the problem goes away?

A good case study doesn’t tell the readers what to think. It guides the reader through the thought process used to create the final conclusion. The readers may come to their own conclusion or find fault in the logic being presented. That’s okay because there may be more than one solution to the problem. The readers will have their own perspective and background as they read the case study.

Describe the solution

This section discusses the solution and the thought processes that lead up to it. It guides the reader through the information to the solution that was implemented. This section may contain the author’s opinions and speculations.

Facts will be involved in the decision, but there can be subjective thinking as well:

“Taking into account A, B and C, the committee suggested solution X. In lieu of the current budget situation, the committee felt this was the most prudent approach”

Briefly present the key elements used to derive the solution. Be clear about the goal of the solution. Was it to slow down, reduce or eliminate the problem?

Evaluate the response to the solution

If the case study is for a recent situation, there may not have been enough time to determine the overall effect of the solution:

“New infection standards were adopted in the first quarter and the center hopes to have enough information by the year’s end to judge their effectiveness”

If the solution has been in place for some time, then an opportunity to gather and review facts and impressions exists. A summary of how well the solution is working would be included here.

Tell the whole story

Case study-writing is about telling the story of a problem that has been fixed. The focus is on the evidence for the problem and the approach used to create a solution. The writing style guides the readers through the problem analysis as if they were part of the project. The result is a case study that can be both entertaining and educational.

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How to Build Case Study SOPs

By our estimates, only 1% of companies manage to publish a steady stream of customer stories. 

Want to join them? 

To build case studies at scale, you need to set up a systematic, step-by-step process for surfacing good candidates, making the ask, and producing a study that will convince prospects and wow leads. 

In other words, you need some standard operating procedures (SOPs) for your case study production process. 

1. What is a case study SOP?

A standard operating procedure is a set of easy-to-understand, step-by-step instructions to help everyone in an organization perform a task. It can look like a checklist, a flowchart, or even an interactive questionnaire. 

SOPs should be part of your case study strategy . They serve as a single source of truth for all things case study-related at your organization. 

Case study SOPs should include: 

• Coverage gaps: What customer success stories does your organization need to empower different teams? 
• Roles and responsibilities: Who owns what piece of the process?
• Templates: Links to templates for making the ask, following up with candidates, or sharing published stories
• Plus, much, much more

2. Why are SOPs important for your case study creation process? 

Case study SOPs accomplish four goals: 

• They align all teams and team members around process and strategy
• They create accountabilities for roles and make it clear who owns what parts of the process
• They simplify access to templates, permission docs, etc.
• They communicate the value and importance of the program

Without this easily-accessible central source of truth, your case study program can start to feel nebulous. It’ll be harder to find new success stories and keep the process moving forward. 

3. Who needs to be involved in creating these SOPs? 

In one word: Everyone . 

One of the challenges for people in marketing—particularly customer advocacy, customer marketing, and product marketing—is that to be successful, you have to get other teams involved. 

By demonstrating you have a process and involving other teams in shaping that process, you are more likely to keep them involved going forward.

Customer success teams are closest to the customer, leadership sets the strategy, sales reps may be most attuned to what customers want and need. They each have valuable insights to contribute. If their priorities are taken into account from the start, you’ll produce better, more valuable assets for everyone.

4. Should every company have these SOPs?

The short answer is yes . Every company, no matter what size, needs case study SOPs if they want to produce studies at scale. Yet it’s surprising how few companies have SOPs in place to help them execute. 

If you’re building any kind of customer referral program, advocacy program, or case study program, SOPs will help those programs scale with you as your company grows. They can help you train new hires faster and more efficiently. The earlier you get this in place, the better it can be woven into other conversations, documentation, and meetings, so that your SOPs can evolve alongside your company. 

Every company, no matter what size, needs case study SOPs if they want to produce studies at scale.

5. why is it important to keep sops up to date.

If your SOPs aren’t live, accessible, and regularly updated, they’ll lose relevance and quickly be forgotten—which defeats the purpose of creating them in the first place. 

An SOP not only brings us all into focus, but it should be something that you refer back to, update, and share. Make it a central point of discussion so your program stays relevant and useful.

Let us help you build your case study SOPs 

If building your SOPs from scratch feels overwhelming, we can help. We’ve helped hundreds of companies through the case study creation process, and we’ve seen firsthand what works—and what doesn’t.

Contact us to start the conversation.

Sam Harrison

Writer and interviewer.

As an interviewer and writer, Sam loves helping people shape their experiences into compelling stories.

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• v.52(4); 2008 Dec

Guidelines to the writing of case studies

Dr. brian budgell.

* Département chiropratique, Université du Québec à Trois-Rivières, 3351, boul des Forges, Trois-Rivières, Qc, Canada G9A 5H7

Dr. Brian Budgell, DC, PhD, JCCA Editorial Board

• Introduction

Case studies are an invaluable record of the clinical practices of a profession. While case studies cannot provide specific guidance for the management of successive patients, they are a record of clinical interactions which help us to frame questions for more rigorously designed clinical studies. Case studies also provide valuable teaching material, demonstrating both classical and unusual presentations which may confront the practitioner. Quite obviously, since the overwhelming majority of clinical interactions occur in the field, not in teaching or research facilities, it falls to the field practitioner to record and pass on their experiences. However, field practitioners generally are not well-practised in writing for publication, and so may hesitate to embark on the task of carrying a case study to publication. These guidelines are intended to assist the relatively novice writer – practitioner or student – in efficiently navigating the relatively easy course to publication of a quality case study. Guidelines are not intended to be proscriptive, and so throughout this document we advise what authors “may” or “should” do, rather than what they “must” do. Authors may decide that the particular circumstances of their case study justify digression from our recommendations.

Additional and useful resources for chiropractic case studies include:

• Waalen JK. Single subject research designs. J Can Chirop Assoc 1991; 35(2):95–97.
• Gleberzon BJ. A peer-reviewer’s plea. J Can Chirop Assoc 2006; 50(2):107.
• Merritt L. Case reports: an important contribution to chiropractic literature. J Can Chiropr Assoc 2007; 51(2):72–74.

Portions of these guidelines were derived from Budgell B. Writing a biomedical research paper. Tokyo: Springer Japan KK, 2008.

General Instructions

This set of guidelines provides both instructions and a template for the writing of case reports for publication. You might want to skip forward and take a quick look at the template now, as we will be using it as the basis for your own case study later on. While the guidelines and template contain much detail, your finished case study should be only 500 to 1,500 words in length. Therefore, you will need to write efficiently and avoid unnecessarily flowery language.

These guidelines for the writing of case studies are designed to be consistent with the “Uniform Requirements for Manuscripts Submitted to Biomedical Journals” referenced elsewhere in the JCCA instructions to authors.

After this brief introduction, the guidelines below will follow the headings of our template. Hence, it is possible to work section by section through the template to quickly produce a first draft of your study. To begin with, however, you must have a clear sense of the value of the study which you wish to describe. Therefore, before beginning to write the study itself, you should gather all of the materials relevant to the case – clinical notes, lab reports, x-rays etc. – and form a clear picture of the story that you wish to share with your profession. At the most superficial level, you may want to ask yourself “What is interesting about this case?” Keep your answer in mind as your write, because sometimes we become lost in our writing and forget the message that we want to convey.

Another important general rule for writing case studies is to stick to the facts. A case study should be a fairly modest description of what actually happened. Speculation about underlying mechanisms of the disease process or treatment should be restrained. Field practitioners and students are seldom well-prepared to discuss physiology or pathology. This is best left to experts in those fields. The thing of greatest value that you can provide to your colleagues is an honest record of clinical events.

Finally, remember that a case study is primarily a chronicle of a patient’s progress, not a story about chiropractic. Editorial or promotional remarks do not belong in a case study, no matter how great our enthusiasm. It is best to simply tell the story and let the outcome speak for itself. With these points in mind, let’s begin the process of writing the case study:

• Title: The title page will contain the full title of the article. Remember that many people may find our article by searching on the internet. They may have to decide, just by looking at the title, whether or not they want to access the full article. A title which is vague or non-specific may not attract their attention. Thus, our title should contain the phrase “case study,” “case report” or “case series” as is appropriate to the contents. The two most common formats of titles are nominal and compound. A nominal title is a single phrase, for example “A case study of hypertension which responded to spinal manipulation.” A compound title consists of two phrases in succession, for example “Response of hypertension to spinal manipulation: a case study.” Keep in mind that titles of articles in leading journals average between 8 and 9 words in length.
• Other contents for the title page should be as in the general JCCA instructions to authors. Remember that for a case study, we would not expect to have more than one or two authors. In order to be listed as an author, a person must have an intellectual stake in the writing – at the very least they must be able to explain and even defend the article. Someone who has only provided technical assistance, as valuable as that may be, may be acknowledged at the end of the article, but would not be listed as an author. Contact information – either home or institutional – should be provided for each author along with the authors’ academic qualifications. If there is more than one author, one author must be identified as the corresponding author – the person whom people should contact if they have questions or comments about the study.
• Key words: Provide key words under which the article will be listed. These are the words which would be used when searching for the article using a search engine such as Medline. When practical, we should choose key words from a standard list of keywords, such as MeSH (Medical subject headings). A copy of MeSH is available in most libraries. If we can’t access a copy and we want to make sure that our keywords are included in the MeSH library, we can visit this address: http://www.ncbi.nlm.nih.gov:80/entrez/meshbrowser.cgi

A narrative abstract consists of a short version of the whole paper. There are no headings within the narrative abstract. The author simply tries to summarize the paper into a story which flows logically.

A structured abstract uses subheadings. Structured abstracts are becoming more popular for basic scientific and clinical studies, since they standardize the abstract and ensure that certain information is included. This is very useful for readers who search for articles on the internet. Often the abstract is displayed by a search engine, and on the basis of the abstract the reader will decide whether or not to download the full article (which may require payment of a fee). With a structured abstract, the reader is more likely to be given the information which they need to decide whether to go on to the full article, and so this style is encouraged. The JCCA recommends the use of structured abstracts for case studies.

Since they are summaries, both narrative and structured abstracts are easier to write once we have finished the rest of the article. We include a template for a structured abstract and encourage authors to make use of it. Our sub-headings will be:

• Introduction: This consists of one or two sentences to describe the context of the case and summarize the entire article.
• Case presentation: Several sentences describe the history and results of any examinations performed. The working diagnosis and management of the case are described.
• Management and Outcome: Simply describe the course of the patient’s complaint. Where possible, make reference to any outcome measures which you used to objectively demonstrate how the patient’s condition evolved through the course of management.
• Discussion: Synthesize the foregoing subsections and explain both correlations and apparent inconsistencies. If appropriate to the case, within one or two sentences describe the lessons to be learned.
• Introduction: At the beginning of these guidelines we suggested that we need to have a clear idea of what is particularly interesting about the case we want to describe. The introduction is where we convey this to the reader. It is useful to begin by placing the study in a historical or social context. If similar cases have been reported previously, we describe them briefly. If there is something especially challenging about the diagnosis or management of the condition that we are describing, now is our chance to bring that out. Each time we refer to a previous study, we cite the reference (usually at the end of the sentence). Our introduction doesn’t need to be more than a few paragraphs long, and our objective is to have the reader understand clearly, but in a general sense, why it is useful for them to be reading about this case.

The next step is to describe the results of our clinical examination. Again, we should write in an efficient narrative style, restricting ourselves to the relevant information. It is not necessary to include every detail in our clinical notes.

If we are using a named orthopedic or neurological test, it is best to both name and describe the test (since some people may know the test by a different name). Also, we should describe the actual results, since not all readers will have the same understanding of what constitutes a “positive” or “negative” result.

X-rays or other images are only helpful if they are clear enough to be easily reproduced and if they are accompanied by a legend. Be sure that any information that might identify a patient is removed before the image is submitted.

At this point, or at the beginning of the next section, we will want to present our working diagnosis or clinical impression of the patient.

It is useful for the reader to know how long the patient was under care and how many times they were treated. Additionally, we should be as specific as possible in describing the treatment that we used. It does not help the reader to simply say that the patient received “chiropractic care.” Exactly what treatment did we use? If we used spinal manipulation, it is best to name the technique, if a common name exists, and also to describe the manipulation. Remember that our case study may be read by people who are not familiar with spinal manipulation, and, even within chiropractic circles, nomenclature for technique is not well standardized.

We may want to include the patient’s own reports of improvement or worsening. However, whenever possible we should try to use a well-validated method of measuring their improvement. For case studies, it may be possible to use data from visual analogue scales (VAS) for pain, or a journal of medication usage.

It is useful to include in this section an indication of how and why treatment finished. Did we decide to terminate care, and if so, why? Did the patient withdraw from care or did we refer them to another practitioner?

• Discussion: In this section we may want to identify any questions that the case raises. It is not our duty to provide a complete physiological explanation for everything that we observed. This is usually impossible. Nor should we feel obligated to list or generate all of the possible hypotheses that might explain the course of the patient’s condition. If there is a well established item of physiology or pathology which illuminates the case, we certainly include it, but remember that we are writing what is primarily a clinical chronicle, not a basic scientific paper. Finally, we summarize the lessons learned from this case.
• Acknowledgments: If someone provided assistance with the preparation of the case study, we thank them briefly. It is neither necessary nor conventional to thank the patient (although we appreciate what they have taught us). It would generally be regarded as excessive and inappropriate to thank others, such as teachers or colleagues who did not directly participate in preparation of the paper.

A popular search engine for English-language references is Medline: http://www.ncbi.nlm.nih.gov/entrez/query.fcgi

• Legends: If we used any tables, figures or photographs, they should be accompanied by a succinct explanation. A good rule for graphs is that they should contain sufficient information to be generally decipherable without reference to a legend.
• Tables, figures and photographs should be included at the end of the manuscript.
• Permissions: If any tables, figures or photographs, or substantial quotations, have been borrowed from other publications, we must include a letter of permission from the publisher. Also, if we use any photographs which might identify a patient, we will need their written permission.

In addition, patient consent to publish the case report is also required.

Running Header:

• Name, academic degrees and affiliation

Name, address and telephone number of corresponding author

Disclaimers

Statement that patient consent was obtained

Sources of financial support, if any

Key words: (limit of five)

Abstract: (maximum of 150 words)

• Case Presentation
• Management and Outcome

Introduction:

Provide a context for the case and describe any similar cases previously reported.

Case Presentation:

• Introductory sentence: e.g. This 25 year old female office worker presented for the treatment of recurrent headaches.
• Describe the essential nature of the complaint, including location, intensity and associated symptoms: e.g. Her headaches are primarily in the suboccipital region, bilaterally but worse on the right. Sometimes there is radiation towards the right temple. She describes the pain as having an intensity of up to 5 out of ten, accompanied by a feeling of tension in the back of the head. When the pain is particularly bad, she feels that her vision is blurred.
• Further development of history including details of time and circumstances of onset, and the evolution of the complaint: e.g. This problem began to develop three years ago when she commenced work as a data entry clerk. Her headaches have increased in frequency in the past year, now occurring three to four days per week.
• Describe relieving and aggravating factors, including responses to other treatment: e.g. The pain seems to be worse towards the end of the work day and is aggravated by stress. Aspirin provides some relieve. She has not sought any other treatment.
• Include other health history, if relevant: e.g. Otherwise the patient reports that she is in good health.
• Include family history, if relevant: e.g. There is no family history of headaches.
• Summarize the results of examination, which might include general observation and postural analysis, orthopedic exam, neurological exam and chiropractic examination (static and motion palpation): e.g. Examination revealed an otherwise fit-looking young woman with slight anterior carriage of the head. Cervical active ranges of motion were full and painless except for some slight restriction of left lateral bending and rotation of the head to the left. These motions were accompanied by discomfort in the right side of the neck. Cervical compression of the neck in the neutral position did not create discomfort. However, compression of the neck in right rotation and extension produced some right suboccipital pain. Cranial nerve examination was normal. Upper limb motor, sensory and reflex functions were normal. With the patient in the supine position, static palpation revealed tender trigger points bilaterally in the cervical musculature and right trapezius. Motion palpation revealed restrictions of right and left rotation in the upper cervical spine, and restriction of left lateral bending in the mid to lower cervical spine. Blood pressure was 110/70. Houle’s test (holding the neck in extension and rotation for 30 seconds) did not produce nystagmus or dizziness. There were no carotid bruits.
• The patient was diagnosed with cervicogenic headache due to chronic postural strain.

Management and Outcome:

• Describe as specifically as possible the treatment provided, including the nature of the treatment, and the frequency and duration of care: e.g. The patient undertook a course of treatment consisting of cervical and upper thoracic spinal manipulation three times per week for two weeks. Manipulation was accompanied by trigger point therapy to the paraspinal muscles and stretching of the upper trapezius. Additionally, advice was provided concerning maintenance of proper posture at work. The patient was also instructed in the use of a cervical pillow.
• If possible, refer to objective measures of the patient’s progress: e.g. The patient maintained a headache diary indicating that she had two headaches during the first week of care, and one headache the following week. Furthermore the intensity of her headaches declined throughout the course of treatment.
• Describe the resolution of care: e.g. Based on the patient’s reported progress during the first two weeks of care, she received an additional two treatments in each of the subsequent two weeks. During the last week of care she experienced no headaches and reported feeling generally more energetic than before commencing care. Following a total of four weeks of care (10 treatments) she was discharged.

Discussion:

Synthesize foregoing sections: e.g. The distinction between migraine and cervicogenic headache is not always clear. However, this case demonstrates several features …

Summarize the case and any lessons learned: e.g. This case demonstrates a classical presentation of cervicogenic headache which resolved quickly with a course of spinal manipulation, supportive soft-tissue therapy and postural advice.

References: (using Vancouver style) e.g.

1 Terret AGJ. Vertebrogenic hearing deficit, the spine and spinal manipulation therapy: a search to validate the DD Palmer/Harvey Lillard experience. Chiropr J Aust 2002; 32:14–26.

Legends: (tables, figures or images are numbered according to the order in which they appear in the text.) e.g.

Figure 1: Intensity of headaches as recorded on a visual analogue scale (vertical axis) versus time (horizontal axis) during the four weeks that the patient was under care. Treatment was given on days 1, 3, 5, 8, 10, 12, 15, 18, 22 and 25. Headache frequency and intensity is seen to fall over time.

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JASPER gave me the confidence to communicate simply

Department of Health and Social Care programme manager Karen Horrocks says the JASPER course reinforced her belief in the value of straightforward language.

Karen Horrocks, Department of Health and Social Care

When Karen Horrocks joined the Civil Service after a career in local government and the NHS, she was initially bewildered by the way some of her colleagues communicated.

“The way some of them spoke and wrote made me feel a bit excluded,” she said.

“Their language was peppered with acronyms and specialist phrases and I never knew whether to query them or to furiously ‘google’ them afterwards.

“It made me feel uneasy and at a disadvantage. I wondered if I should be speaking and writing that way too.”

Foundations of writing in government

This uncertainty was one reason Karen, a public health expert based in Leeds, opted to do the Foundations of Writing in Government (JASPER) course .

JASPER is one of Government Campus’ most highly rated courses. It is free on Civil Service Learning and comprises four hours of bite-size learning that can be done at the learner’s own pace.

Sensible communications

“The course reiterated the sensible communications skills I had learnt in previous roles and gave me confidence to write using short sentences and simple language,” she said.

“My colleagues and I frequently discuss how certain words and phrases mean very little to those outside a specific ‘bubble’. For example, I’m not sure how many people truly understand a jargon phrase like ‘socialising policy’. 

“What JASPER gave me was the confidence to choose simpler language over specialist jargon. It teaches you the essential skills for communicating effectively and with impact and is a course I recommend.”

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• Open access
• Published: 07 September 2024

A case study of the informative value of risk of bias and reporting quality assessments for systematic reviews

• Cathalijn H. C. Leenaars   ORCID: orcid.org/0000-0002-8212-7632 1 ,
• Frans R. Stafleu 2 ,
• Christine Häger 1 &
• André Bleich 1  

Systematic Reviews volume  13 , Article number:  230 ( 2024 ) Cite this article

Metrics details

While undisputedly important, and part of any systematic review (SR) by definition, evaluation of the risk of bias within the included studies is one of the most time-consuming parts of performing an SR. In this paper, we describe a case study comprising an extensive analysis of risk of bias (RoB) and reporting quality (RQ) assessment from a previously published review (CRD42021236047). It included both animal and human studies, and the included studies compared baseline diseased subjects with controls, assessed the effects of investigational treatments, or both. We compared RoB and RQ between the different types of included primary studies. We also assessed the “informative value” of each of the separate elements for meta-researchers, based on the notion that variation in reporting may be more interesting for the meta-researcher than consistently high/low or reported/non-reported scores. In general, reporting of experimental details was low. This resulted in frequent unclear risk-of-bias scores. We observed this both for animal and for human studies and both for disease-control comparisons and investigations of experimental treatments. Plots and explorative chi-square tests showed that reporting was slightly better for human studies of investigational treatments than for the other study types. With the evidence reported as is, risk-of-bias assessments for systematic reviews have low informative value other than repeatedly showing that reporting of experimental details needs to improve in all kinds of in vivo research. Particularly for reviews that do not directly inform treatment decisions, it could be efficient to perform a thorough but partial assessment of the quality of the included studies, either of a random subset of the included publications or of a subset of relatively informative elements, comprising, e.g. ethics evaluation, conflicts of interest statements, study limitations, baseline characteristics, and the unit of analysis. This publication suggests several potential procedures.

Peer Review reports

Introduction

Researchers performing systematic reviews (SRs) face bias at two potential levels: first, at the level of the SR methods themselves, and second, at the level of the included primary studies [ 1 ]. To safeguard correct interpretation of the review’s results, transparency is required at both levels. For bias at the level of the SR methods, this is ensured by transparent reporting of the full SR methods, at least to the level of detail as required by the PRISMA statement [ 2 ]. For bias at the level of the included studies, study reporting quality (RQ) and/or risk of bias (RoB) are evaluated at the level of the individual included study. Specific tools are available to evaluate RoB in different study types [ 3 ]. Also, for reporting of primary studies, multiple guidelines and checklists are available to prevent missing important experimental details and more become available for different types of studies over time [ 4 , 5 ]. Journal endorsement of these types of guidelines has been shown to improve study reporting quality [ 6 ].

While undisputedly important, evaluation of the RoB and/or RQ of the included studies is one of the most time-consuming parts of an SR. Experienced reviewers need 10 min to an hour to complete an individual RoB assessment [ 7 ], and every included study needs to be evaluated by two reviewers. Besides spending substantial amounts of time on RoB or RQ assessments, reviewers tend to become frustrated because of the scores frequently being unclear or not reported (personal experience from the authors, colleagues and students). While automation of RoB seems to be possible without loss of accuracy [ 8 , 9 ], so far, this automation has not had significant impact on the speed; in a noninferiority randomised controlled trial of the effect of automation on person-time spent on RoB assessment, the confidence interval for the time saved ranged from − 5.20 to + 2.41 min [ 8 ].

In any scientific endeavour, there is a balance between reliability and speed; to guarantee reliability of a study, time investments are necessary. RoB or RQ assessment is generally considered to be an essential part of the systematic review process to warrant correct interpretation of the findings, but with so many studies scoring “unclear” or “not reported”, we wondered if all this time spent on RoB assessments is resulting in increased reliability of reviews.

Overall unclear risk of bias in the included primary studies is a conclusion of multiple reviews, and these assessments are useful in pinpointing problems in reporting, thereby potentially improving the quality of future publications of primary studies. However, the direct goal of most SRs is to answer a specific review question, and in that respect, unclear RoB/not reported RQ scores contribute little to the validity of the review’s results. If all included studies score “unclear” or “high” RoB on at least one of the analysed elements, the overall effect should be interpreted as inconclusive.

While it is challenging to properly evaluate the added validity value of a methodological step, we had data available allowing for an explorative case study to assess the informative value of various RoB and RQ elements in different types of studies. We previously performed an SR of the nasal potential difference (nPD) for cystic fibrosis (CF) in animals and humans, aiming to quantify the predictive value of animal models for people with CF [ 10 , 11 ]. That review comprised between-subject comparisons of both baseline versus disease-control and treatment versus treatment control. For that review, we performed full RoB and RQ analyses. This resulted in data allowing for comparisons of RoB and RQ between animal and human studies, but also between baseline and treatment studies, which are both presented in this manuscript. RoB evaluations were based on the Cochrane collaboration’s tool [ 12 ] for human studies and SYRCLE’s tool [ 13 ] for animal studies. RQ was tested based on the ARRIVE guidelines [ 14 ] for animal studies and the 2010 CONSORT guidelines [ 15 ] for human studies. Brief descriptions of these tools are provided in Table  1 .

All these tools are focussed on interventional studies. Lacking more specific tools for baseline disease-control comparisons, we applied them as far as relevant for the baseline comparisons. We performed additional analyses on our RQ and RoB assessments to assess the amount of distinctive information gained from them.

The analyses described in this manuscript are based on a case study SR of the nPD related to cystic fibrosis (CF). That review was preregistered on PROSPERO (CRD42021236047) on 5 March 2021 [ 16 ]. Part of the results were published previously [ 10 ]. The main review questions are answered in a manuscript that has more recently been published [ 11 ]. Both publications show a simple RoB plot corresponding to the publication-specific results.

For the ease of the reader, we provide a brief summary of the overall review methods. The full methods have been described in our posted protocol [ 16 ] and the earlier publications [ 10 , 11 ]. Comprehensive searches were performed in PubMed and Embase, unrestricted for publication date or language, on 23 March 2021. Title-abstract screening and full-text screening were performed by two independent reviewers blinded to the other’s decision (FS and CL) using Rayyan [ 17 ]. We included animal and/or human studies describing nPD in CF patients and/or CF animal models. We restricted to between-subject comparisons, either CF versus healthy controls or experimental CF treatments versus CF controls. Reference lists of relevant reviews and included studies were screened (single level) for snowballing. Discrepancies were all resolved by discussions between the reviewers.

Data were extracted by two independent reviewers per reference in several distinct phases. Relevant to this manuscript, FS and CL extracted RoB and RQ data in Covidence [ 18 ], in two separate projects using the same list of 48 questions for studies assessing treatment effects and studies assessing CF-control differences. The k  = 11 studies that were included in both parts of the overarching SR were included twice in the current data set, as RoB was separately scored for each comparison. Discrepancies were all resolved by discussions between the reviewers. In violation of the protocol, no third reviewer was involved.

RoB and SQ data extraction followed our review protocol, which states the following: “For human studies, risk of bias will be assessed with the Cochrane Collaboration’s tool for assessing risk of bias. For animal studies, risk of bias will be assessed with SYRCLE’s RoB tool. Besides, we will check compliance with the ARRIVE and CONSORT guidelines for reporting quality”. The four tools contain overlapping questions. To prevent unnecessary repetition of our own work, we created a single list of 48 items, which were ordered by topic for ease of extraction. For RoB, this list contains the same elements as the original tools, with the same response options (high/unclear/low RoB). For RQ, we created checklists with all elements as listed in the original tools, with the response options reported yes/no. For (RQ and RoB) elements specific to some of the included studies, the response option “irrelevant” was added. We combined these lists, only changing the order and merging duplicate elements. We do not intend this list to replace the individual tools; it was created for this specific study only.

In our list, each question was preceded by a short code indicating the tool it was derived from (A for ARRIVE, C for CONSORT, and S for SYRCLE’s) to aid later analyses. When setting up, we started with the animal-specific tools, with which the authors are more familiar. After preparing data extraction for those, we observed that all elements from the Cochrane tool had already been addressed. Therefore, this list was not explicit in our extractions. The extraction form always allowed free text to support the response. Our extraction list is provided with our supplementary data.

For RoB, the tools provide relatively clear suggestions for which level to score and when, with signalling questions and examples [ 12 , 13 ]. However, this still leaves some room for interpretation, and while the signalling questions are very educative, there are situations where the response would in our opinion not correspond to the actual bias. The RQ tools have been developed as guidelines on what to report when writing a manuscript, and not as a tool to assess RQ [ 14 , 15 ]. This means we had to operationalise upfront which level we would find sufficient to score “reported”. Our operationalisations and corrections of the tools are detailed in Table  2 .

Data were exported from Covidence into Microsoft’s Excel, where the two projects were merged and spelling and capitalisation were harmonised. Subsequent analyses were performed in R [ 21 ] version 4.3.1 (“Beagle Scouts”) via RStudio [ 22 ], using the following packages: readxl [ 23 ], dplyr [ 24 ], tidyr [ 25 ], ggplot2 [ 26 ], and crosstable [ 27 ].

Separate analyses were performed for RQ (with two levels per element) and RoB (with three levels per element). For both RoB and RQ, we first counted the numbers of irrelevant scores overall and per item. Next, irrelevant scores were deleted from further analyses. We then ranked the items by percentages for reported/not reported, or for high/unclear/low scores, and reported the top and bottom 3 (RoB) or 5 (RQ) elements.

While 100% reported is most informative to understand what actually happened in the included studies, if all authors continuously report a specific element, scoring of this element for an SR is not the most informative for meta-researchers. If an element is not reported at all, this is bad news for the overall level of confidence in an SR, but evaluating it per included study is also not too efficient except for highlighting problems in reporting, which may help to improve the quality of future (publications of) primary studies. For meta-researchers, elements with variation in reporting may be considered most interesting because these elements highlight differences between the included studies. Subgroup analyses based on specific RQ/RoB scores can help to estimate the effects of specific types of bias on the overall effect size observed in meta-analyses, as has been done for example randomisation and blinding [ 28 ]. However, these types of subgroup analyses are only possible if there is some variation in the reporting. Based on this idea, we defined a “distinctive informative value” (DIV) for RQ elements, based on the optimal variation being 50% reported and either 0% or 100% reporting being minimally informative. Thus, this “DIV” was calculated as follows:

Thus, the DIV could range from 0 (no informative value) to 50 (maximally informative), visualised in Fig.  1 .

Visual explanation of the DIV value

The DIV value was only used for ranking. The results were visualised in a heatmap, in which the intermediate shades correspond to high DIV values.

For RoB, no comparable measure was calculated. With only 10 elements but at 3 distinct levels, we thought a comparable measure would sooner hinder interpretation of informative value than help it. Instead, we show the results in an RoB plot split by population and study design type.

Because we are interested in quantifying the predictive value of animal models for human patients, we commonly perform SRs including both animal and human data (e.g. [ 29 , 30 ]). The dataset described in the current manuscript contained baseline and intervention studies in animals and humans. Because animal studies are often held responsible for the reproducibility crisis, but also to increase the external validity of this work, explorative chi-square tests (the standard statistical test for comparing percentages for binary variables) were performed to compare RQ and RoB between animal and human studies and between studies comparing baselines and treatment effects. They were performed with the base R “chisq.test” function. No power calculations were performed, as these analyses were not planned.

Literature sample

We extracted RoB and RQ data from 164 studies that were described in 151 manuscripts. These manuscripts were published from 1981 through 2020. Overall, 164 studies comprised 78 animal studies and 86 human studies, 130 comparisons of CF versus non-CF control, and 34 studies assessing experimental treatments. These numbers are detailed in a crosstable (Table  3 ).

The 48 elements in our template were completed for these 164 studies, which results in 7872 assessed elements. In total, 954 elements (12.1%) were irrelevant for various reasons (mainly for noninterventional studies and for human studies). The 7872 individual scores per study are available from the data file on OSF.

Of the 48 questions in our extraction template, 38 addressed RQ, and 10 addressed RoB.

Overall reporting quality

Of the 6232 elements related to RQ, 611 (9.8%) were deemed irrelevant. Of the remainder, 1493 (26.6% of 5621) were reported. The most reported elements were background of the research question (100% reported), objectives (98.8% reported), interpretation of the results (98.2% reported), generalisability (86.0% reported), and the experimental groups (83.5% reported). The least-reported elements were protocol violations, interim analyses + stopping rules and when the experiments were performed (all 0% reported), where the experiments were performed (0.6% reported), and all assessed outcome measures (1.2% reported).

The elements with most distinctive variation in reporting (highest DIV, refer to the “ Methods ” section for further information) were as follows: ethics evaluation (64.6% reported), conflicts of interest (34.8% reported), study limitations (29.3% reported), baseline characteristics (26.2% reported), and the unit of analysis (26.2% reported). RQ elements with DIV values over 10 are shown in Table  4 .

Overall risk of bias

Of the 1640 elements related to RoB, 343 (20.9%) were deemed irrelevant. Of the remainder, 219 (16.9%) scored high RoB, and 68 (5.2%) scored low RoB. The overall RoB scores were highest for selective outcome reporting (97.6% high), baseline group differences (19.5% high), and other biases (9.8% high); lowest for blinding of participants, caregivers, and investigators (13.4% low); blinding of outcome assessors (11.6% low) and baseline group differences (8.5% low); and most unclear for bias due to animal housing (100% unclear), detection bias due to the order of outcome measurements (99.4% unclear), and selection bias in sequence generation (97.1% unclear). The baseline group differences being both in the highest and the lowest RoB score are explained by the baseline values being reported better than the other measures, resulting in fewer unclear scores.

Variation in reporting is relatively high for most of the elements scoring high or low. Overall distinctive value of the RoB elements is low, with most scores being unclear (or, for selective outcome reporting, most scores being high).

Animal versus human studies

For RQ, the explorative chi-square tests indicated differences in reporting between animal and human studies for baseline values ( Χ 1  = 50.3, p  < 0.001), ethical review ( Χ 1  = 5.1, p  = 0.02), type of study ( Χ 1  = 11.2, p  < 0.001), experimental groups ( Χ 1  = 3.9, p  = 0.050), inclusion criteria ( Χ 1  = 24.6, p  < 0.001), the exact n value per group and in total ( Χ 1  = 26.0, p  < 0.001), (absence of) excluded datapoints ( Χ 1  = 4.5, p  = 0.03), adverse events ( Χ 1  = 5.5, p  = 0.02), and study limitations ( Χ 1  = 8.2, p  = 0.004). These explorative findings are visualised in a heatmap (Fig.  2 ).

Heatmap of reporting by type of study. Refer to Table  3 for absolute numbers of studies per category

For RoB, the explorative chi-square tests indicated differences in risk of bias between animal and human studies for baseline differences between the groups ( Χ 2  = 34.6, p  < 0.001) and incomplete outcome data ( Χ 2  = 7.6, p  = 0.02). These explorative findings are visualised in Fig.  3 .

Risk of bias by type of study. Refer to Table  3 for absolute numbers of studies per category. Note that the data shown in these plots overlap with those in the two preceding publications [ 10 , 11 ]

Studies assessing treatment effects versus studies assessing baseline differences

For RQ, the explorative chi-square tests indicated differences in reporting between comparisons of disease with control versus comparisons of treatment effects for the title listing the type of study ( X 1  = 5.0, p  = 0.03), the full paper explicitly mentioning the type of study ( X 1  = 14.0, p  < 0.001), explicit reporting of the primary outcome ( X 1  = 11.7, p  < 0.001), and reporting of adverse events X 1  = 25.4, p  < 0.001). These explorative findings are visualised in Fig.  2 .

For RoB, the explorative chi-square tests indicated differences in risk of bias between comparisons of disease with control versus comparisons of treatment effects for baseline differences between the groups ( Χ 2  = 11.4, p  = 0.003), blinding of investigators and caretakers ( Χ 2  = 29.1, p  < 0.001), blinding of outcome assessors ( Χ 2  = 6.2, p  = 0.046), and selective outcome reporting ( Χ 2  = 8.9, p  = 0.01). These explorative findings are visualised in Fig.  3 .

Overall, our results suggest lower RoB and higher RQ for human treatment studies compared to the other study types.

This literature study shows that reporting of experimental details is low, frequently resulting in unclear risk-of-bias assessments. We observed this both for animal and for human studies, with two main study designs: disease-control comparisons and, in a smaller sample, investigations of experimental treatments. Overall reporting is slightly better for elements that contribute to the “story” of a publication, such as the background of the research question, interpretation of the results and generalisability, and worst for experimental details that relate to differences between what was planned and what was actually done, such as protocol violations, interim analyses, and assessed outcome measures. The latter also results in overall high RoB scores for selective outcome reporting.

Of note, we scored this more stringently than SYRCLE’s RoB tool [ 13 ] suggests and always scored a high RoB if no protocol was posted, because only comparing the “Methods” and “Results” sections within a publication would, in our opinion, result in an overly optimistic view. Within this sample, only human treatment studies reported posting protocols upfront [ 31 , 32 ]. In contrast to selective outcome reporting, we would have scored selection, performance, and detection bias due to sequence generation more liberally for counterbalanced designs (Table  2 ), because randomisation is not the only appropriate method for preventing these types of bias. Particularly when blinding is not possible, counterbalancing [ 33 , 34 ] and Latin-square like designs [ 35 ] can decrease these biases, while randomisation would risk imbalance between groups due to “randomisation failure” [ 36 , 37 ]. We would have scored high risk of bias for blinding for these types of designs, because of increased sequence predictability. However, in practice, we did not include any studies reporting Latin-square-like or other counterbalancing designs.

One of the “non-story” elements that is reported relatively well, particularly for human treatment studies, is the blinding of participants, investigators, and caretakers. This might relate to scientists being more aware of potential bias of participants; they may consider themselves to be more objective than the general population, while the risk of influencing patients could be considered more relevant.

The main strength of this work is that it is a full formal analysis of RoB and RQ in different study types: animal and human, baseline comparisons, and treatment studies. The main limitation is that it is a single case study from a specific topic: the nPD test in CF. The results shown in this paper are not necessarily valid for other fields, particularly as we hypothesise that differences in scientific practice between medical fields relate to differences in translational success [ 38 ]. Thus, it is worth to investigate field-specific informative values before selecting which elements to score and analyse in detail.

Our comparisons of different study and population types show lower RoB and higher RQ for human treatment studies compared to the other study types for certain elements. Concerning RQ, the effects were most pronounced for the type of experimental design being explicitly mentioned and the reporting of adverse events. Concerning RoB, the effects were most pronounced for baseline differences between the groups, blinding of investigators and caretakers, and selective outcome reporting. Note, however, that the number of included treatment studies is a lot lower than the number of included baseline studies, and that the comparisons were based on only k  = 12 human treatment studies. Refer to Table  3 for absolute numbers of studies per category. Besides, our comparisons may be confounded to some extent by the publication date. The nPD was originally developed for human diagnostics [ 39 , 40 ], and animal studies only started to be reported at a later date [ 41 ]. Also, the use of the nPD as an outcome in (pre)clinical trials of investigational treatments originated at a later date [ 42 , 43 ].

Because we did not collect our data to assess time effects, we did not formally analyse them. However, we had an informal look at the publication dates by RoB score for blinding of the investigators and caretakers, and by RQ score for ethics evaluation (in box plots with dot overlay), showing more reported and fewer unclear scores in the more recent publications (data not shown). While we thus cannot rule out confounding of our results by publication date, the results are suggestive of mildly improved reporting of experimental details over time.

This study is a formal comparison of RoB and RQ scoring for two main study types (baseline comparisons and investigational treatment studies), for both animals and humans. Performing these comparisons within the context of a single SR [ 16 ] resulted in a small, but relatively homogeneous sample of primary studies about the nPD in relation to CF. On conferences and from colleagues in the animal SR field, we heard that reporting would be worse for animal than for human studies. Our comparisons allowed us to show that particularly for baseline comparisons of the nPD in CF versus control, this is not the case.

The analysed tools [ 12 , 13 , 15 ] were developed for experimental interventional studies. While some of the elements are less appropriate for other types of studies, such as animal model comparisons, our results show that many of the elements can be used and could still be useful, particularly if the reporting quality of the included studies would be better.

Implications

To correctly interpret the findings of a meta-analysis, awareness of the RoB in the included studies is more relevant than the RQ on its own. However, it is impossible to evaluate the RoB if the experimental details have not been reported, resulting in many unclear scores. With at least one unclear or high RoB score per included study, the overall conclusions of the review become inconclusive. For SRs of overall treatment effects that are performed to inform evidence-based treatment guidelines, RoB analyses remain crucial, even though the scores will often be unclear. Ideally, especially for SRs that will be used to plan future experiments/develop treatment guidelines, analyses should only include those studies consistently showing low risk of bias (i.e. low risk on all elements). However, in practice, consistently low RoB studies in our included literature samples (> 20 SRs to date) are too scarce for meaningful analyses. For other types of reviews, we think it is time to consider if complete RoB assessment is the most efficient use of limited resources. While these assessments regularly show problems in reporting, which may help to improve the quality of future primary studies, the unclear scores do not contribute much to understanding the effects observed in meta-analyses.

With PubMed already indexing nearly 300,000 mentioning the term “systematic review” in the title, abstract, or keywords, we can assume that many scientists are spending substantial amounts of time and resources on RoB and RQ assessments. Particularly for larger reviews, it could be worthwhile to restrict RoB assessment to either a random subset of the included publications or a subset of relatively informative elements. Even a combination of these two strategies may be sufficiently informative if the results of the review are not directly used to guide treatment decisions. The subset could give a reasonable indication of the overall level of evidence of the SR while saving resources. Different suggested procedures are provided in Table  5 . The authors of this work would probably have changed to such a strategy during their early data extraction phase, if the funder would not have stipulated full RoB assessment in their funding conditions.

We previously created a brief and simple taxonomy of systematised review types [ 44 ], in which we advocate RoB assessments to be a mandatory part of any SR. We would still urge anyone calling their review “systematic” to stick to this definition and perform some kind of RoB and/or RQ assessment, but two independent scientists following a lengthy and complex tool for all included publications, resulting in 74.6% of the assessed elements not being reported, or 77.9% unclear RoB, can, in our opinion, in most cases be considered inefficient and unnecessary.

Our results show that there is plenty of room for improvement in the reporting of experimental details in medical scientific literature, both for animal and for human studies. With the current status of the primary literature as it is, full RoB assessment may not be the most efficient use of limited resources, particularly for SRs that are not directly used as the basis for treatment guidelines or future experiments.

Availability of data and materials

The data described in this study are available from the Open Science Platform ( https://osf.io/fmhcq/ ) in the form of a spreadsheet file. In the data file, the first tab shows the list of questions that were used for data extraction with their respective short codes. The second tab shows the full individual study-level scores, with lines per study and columns per short code.

Abbreviations

• Cystic fibrosis

High risk of bias

Low risk of bias

No, not reported

• Nasal potential difference
• Risk of bias
• Reporting quality

Systematic review

Unclear risk of bias

Yes, reported

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Leenaars, C.H.C., Stafleu, F.R., Häger, C. et al. A case study of the informative value of risk of bias and reporting quality assessments for systematic reviews. Syst Rev 13 , 230 (2024). https://doi.org/10.1186/s13643-024-02650-w

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A pressure sensing device to assist in colonoscopic procedures to prevent perforation—a case study.

1. Introduction

2. materials and methods, 2.1. pressure sensing module, 2.2. experiments and data acquisitions, 2.3. signal processing, 3.1. processed signals, 3.2. effectiveness test—a case study, 4. discussion, 5. conclusions, author contributions, institutional review board statement, informed consent statement, data availability statement, conflicts of interest.

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Kim, S.-E.; Kang, Y.-j.; Jung, C.-h.; Jeon, Y.; Jung, Y.; Lee, M.G. A Pressure Sensing Device to Assist in Colonoscopic Procedures to Prevent Perforation—A Case Study. Sensors 2024 , 24 , 5711. https://doi.org/10.3390/s24175711

Kim S-E, Kang Y-j, Jung C-h, Jeon Y, Jung Y, Lee MG. A Pressure Sensing Device to Assist in Colonoscopic Procedures to Prevent Perforation—A Case Study. Sensors . 2024; 24(17):5711. https://doi.org/10.3390/s24175711

Kim, Se-Eun, Young-jae Kang, Chang-ho Jung, Yongho Jeon, Yunho Jung, and Moon Gu Lee. 2024. "A Pressure Sensing Device to Assist in Colonoscopic Procedures to Prevent Perforation—A Case Study" Sensors 24, no. 17: 5711. https://doi.org/10.3390/s24175711

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• Published: 03 September 2024

RNAseqCovarImpute: a multiple imputation procedure that outperforms complete case and single imputation differential expression analysis

• Brennan H. Baker 1 , 2 ,
• Sheela Sathyanarayana 1 , 2 , 3 , 4 ,
• Adam A. Szpiro 5   na1 ,
• James W. MacDonald 1   na1 &
• Alison G. Paquette 1 , 3 , 6   na1  

Genome Biology volume  25 , Article number:  236 ( 2024 ) Cite this article

Metrics details

Missing covariate data is a common problem that has not been addressed in observational studies of gene expression. Here, we present a multiple imputation method that accommodates high dimensional gene expression data by incorporating principal component analysis of the transcriptome into the multiple imputation prediction models to avoid bias. Simulation studies using three datasets show that this method outperforms complete case and single imputation analyses at uncovering true positive differentially expressed genes, limiting false discovery rates, and minimizing bias. This method is easily implemented via an R Bioconductor package, RNAseqCovarImpute that integrates with the limma-voom pipeline for differential expression analysis.

Missing data is a common problem in observational studies, as modeling techniques such as linear regression cannot be fit to data with missing points. Missing data is frequently handled using complete case (CC) analyses in which any individuals with missing data are dropped from the study. Dropping participants can reduce statistical power and, in some cases, result in biased model estimates. A common technique to address these problems is to replace or “impute” missing data points with substituted values. Typically, for a given covariate, missing data points are imputed using a prediction model including other relevant covariates as independent variables. In single imputation (SI), a missing value is replaced with the most likely value based on the predictive model. Statistical efficiency can be improved by including the outcome in the predictive model in addition to covariates. However, in this setting, SI methods can result in biased coefficients and over-confident standard errors [ 1 ]. Multiple imputation (MI) addresses this problem by generating several predictions, thereby allowing for uncertainty about the imputed data to propagate through the analysis. In a typical MI procedure: (1) m imputed data sets are created, (2) each data set is analyzed separately (e.g., using linear regression), and (3) estimates and standard errors across the m analyses are pooled using Rubin’s rules [ 2 , 3 ].

To date, there has been no concerted effort to determine the most advantageous method for handling missing covariate data in transcriptomic studies. A large proportion of RNA-sequencing studies are conducted in in vitro or in vivo models and do not suffer from missing covariate data. Complete datasets are common in experimental studies with controlled conditions and a limited number of covariates. In an experimental setting, studies may employ two-group analyses with no additional variables or utilize covariates for which collecting data is trivial (e.g., sequencing batch and sex). However, the cost of sequencing has decreased over time [ 4 ], and transcriptomic data are already becoming more common in large human observational studies where missing data is a prevailing concern [ 5 , 6 ]. Therefore, guidelines for handling missing data in this context are critically needed to facilitate the integration of transcriptomic and epidemiologic approaches.

While SI methods must omit the outcome from the imputation predictive model to avoid bias, the opposite is true of MI [ 7 ]. However, including the outcome in the MI predictive model can be problematic in “omics” studies with high dimensional data. Fitting an imputation model where the number of independent variables is far greater than the number of individuals in the study is generally not feasible. For instance, in RNA-sequencing studies with tens of thousands of genes, an equal or greater number of participants may be needed to apply a standard MI procedure.

To ensure that outcome data are included in the predictive model (a requirement of MI to avoid bias [ 7 ]), one solution is to make one set of m imputed datasets per gene, where expression data for a single gene is included in the predictive model. Then, each set of imputed data can be used to estimate differential expression of the gene that was used in that set’s predictive modeling. However, the generation of tens of thousands of sets of imputed data is computationally intensive and may require an unfeasible amount of model checking and diagnostics. In epigenetic studies of DNA methylation at CpG cites, this approach has been modified to be less computationally intensive by using groups of CpG sites together to impute missing data [ 8 , 9 ]. We propose an alternative solution for applying MI to high dimensional gene expression data, which is to utilize principal component analysis (PCA) to reduce the dimensionality of the transcriptome. Then, the top PCs can be included in the MI prediction model when imputing missing covariates, satisfying the requirement that outcome information is included in the MI predictive models.

Here, we developed the first method to our knowledge to make MI compatible with high dimensional transcriptomic data. We created an R package (RNAseqCovarImpute) that is fully compatible with the popular limma-voom [ 10 , 11 , 12 ] differential expression analysis pipeline. We conducted a simulation study to compare the performance of MI as implemented in RNAseqCovarImpute with random forest SI and CC analyses. Finally, we applied RNAseqCovarImpute to two analyses involving (1) the placental transcriptome associated with maternal age, and (2) the blood platelet transcriptome associated with colorectal carcinoma.

Multiple imputation and differential expression analysis in the RNAseqCovarImpute package

The RNAseqCovarImpute package includes two methods accommodating the requirement of MI that the outcome data are included in the MI predictive models. The first method surmounts the problem of high-dimensional outcome data by binning genes into smaller groups to analyze pseudo-independently (MI Gene Bin method, see Additional file 1: Supplemental Methods). Analyzing smaller bins of genes independently lowers the dimensionality of the outcome gene expression data, allowing us to include it in the MI predictive modeling. However, binning genes into smaller groups is computationally inefficient, as it requires that the MI and limma-voom analysis is run many times (typically hundreds).

A second method uses PCA to avoid binning genes while still retaining outcome information in the MI models. The MI PCA method implements covariate MI in gene expression studies by (1) performing PCA on the normalized log-counts per million (logCPM) for all genes using the Bioconductor “PCAtools” package [ 13 ]; (2) creating m imputed datasets where the imputation predictor matrix includes all covariates and the optimum number of PCs to retain; (3) conducting the standard limma-voom differential expression analysis pipeline in R with the “limma::voom” followed by “limma::lmFit” followed by “limma::eBayes” functions [ 10 , 11 , 12 ] on each m imputed dataset; (4) pooling the results with Rubin’s rules to produce combined coefficients, standard errors, and P values; and (5) adjusting P values for multiplicity to account for false discovery rate (FDR) (Fig.  1 ; see “  Methods ” for details). Various methods for determining the number of PCs to retain in the MI prediction model can be utilized. For example, Horn’s parallel analysis, which retains PCs with eigenvalues greater than eigenvalues of random data [ 14 , 15 ], utilizing an 80% explained variation cutoff, or the elbow method.

Overview of RNAseqCovarImpute multiple imputation differential expression analysis. A Inputs are covariates, including the predictor of interest and adjustment variables, and RNA-sequencing counts that are filtered to remove low counts and normalized as log-counts per million (logCPM). The logCPM calculation uses the effective library sizes calculated using the weighted trimmed mean of M-values method. B Principal component analysis (PCA) is used to reduce the dimensionality of the count matrix and Horn’s parallel analysis determines the number of PCs (1-h) to retain. Retained PCs (PC1-PCh) are added to the input dataset of covariates (C1-Cn). C Multiple imputation imputes missing covariate data m times (RNA-sequencing data are not imputed). All covariates and all retained PCs are included in the imputation prediction models. D Associations are estimated between the covariates and gene expression, according to the user’s statistical model design of interest, separately within each m imputed dataset using voom followed by lmFit followed by eBayes functions. In this example, the design is a multivariable linear model including all covariates C1-Cn. E Combine across m sets of model results using Rubin’s rules to produce combined log fold changes, standard errors, and P values for each term in the design

Three versions of MI PCA using different criteria to determine the number of retained PCs were compared with the MI Gene Bin approach (“  Methods ”). MI PCA using Horn’s parallel analysis performed better than the MI Gene Bin and other MI PCA methods. All methods had similar true positive rates (TPRs), while MI PCA horn had the lowest false positive rates (FPRs) across most scenarios (Additional file 1: Supplemental Results, Additional file 1: Figs. S2–S4). Among the methods for retaining PCs, results were relatively comparable when missing data were minimal. For instance, for the ECHO-PATHWAYS dataset, Horn’s parallel analysis retained 35 PCs, an 80% variance explained cutoff retained 213 PCs, and the elbow method retained 15 PCs. Despite substantial differences in the number of retained PCs, all methods had similarly high TPRs and good FPR control at approximately 0.05 when there was only 5–15% missing data (Additional file 1: Fig. S2). However, when levels of missing data were higher, FPRs were consistently controlled at 0.05 for Horn’s parallel analysis, but not for the 80% variance explained or elbow approaches (Additional file 1: Fig. S2). Thus, MI PCA using Horn’s parallel analysis was selected as the MI method of choice (hereinafter the “RNAseqCovarImpute” method).

Performance on three real datasets following simulations of missing covariate data

Three large real-world RNA-sequencing datasets encompassing multiple tissue types and a diverse range of covariates were utilized to compare RNAseqCovarImpute, SI, and CC differential expression analysis (“  Methods ”). 

The ECHO prenatal and early childhood pathways to health (ECHO-PATHWAYS) dataset (dbGaP phs003619.v1.p1 and phs003620.v1.p1) includes RNA-sequencing of placentas sampled at delivery from socioeconomically and racially/ethnically diverse participants from two regionally distinct birth cohorts in Washington (Seattle and Yakima) and Tennessee (Memphis), USA [ 5 ]. For the ECHO-PATHWAYS dataset (N = 994), maternal age served as the predictor of interest in differential expression analysis, while covariates included fetal sex, RNA-sequencing batch, maternal tobacco use during pregnancy, maternal alcohol use during pregnancy, and family income. 

The non-small cell lung cancer (NSCLC) dataset (EMBL-EBI: E-GEOD-81089) includes RNA-sequencing of both lung tumor and non-malignant tissues sampled from patients diagnosed with NSCLC being surgically treated from 2006 to 2010 at the Uppsala University Hospital, Sweden [ 16 ]. For the NSCLC dataset (N = 670), the predictor of interest was sex, while covariates included participant age, participant smoking status, and sampling site (tumor versus non-malignant). The non-small cell lung cancer (NSCLC) dataset (EMBL-EBI: E-GEOD-81089) includes RNA-sequencing of both lung tumor and non-malignant tissues sampled from patients diagnosed with NSCLC being surgically treated from 2006 to 2010 at the Uppsala University Hospital, Sweden [ 16 ]. For the NSCLC dataset (N = 670), the predictor of interest was sex, while covariates included participant age, participant smoking status, and sampling site (tumor versus non-malignant).

The Epstein-Barr virus (EBV) dataset (EMBL-EBI: E-MTAB-7805) analyzed primary cultures of human B lymphocytes obtained from adenoid tissue [ 17 ]. For the EBV dataset ( N  = 384), the predictor of interest was time elapsed in culture, while covariates included EBV infection status and individual donor source.

The ECHO-PATHWAYS dataset included 14,026 genes after filtering, of which 2517 were significantly associated with maternal age in the full data model (true positives) while adjusting for covariates. Following the full data model, simulations to induce missingness in the covariate data were performed 10 times per level of missing data and missingness mechanism (“  Methods ”). Patterns of simulated missing data depended on the missingness mechanism. When data were simulated to be missing at random (MAR) or missing not at random (MNAR), the maternal alcohol and family income variables had strong influence over patterns of missing data as intended. For example, in the simulated datasets where 55% of individuals had at least one missing data point, the average rate of individuals with at least one missing data point was 91% among alcohol users but only 50% among those reporting no alcohol use. Family income also impacted missingness: the missing data rate was 37% among those in the bottom quartile of family income, but 75% among those in the top quartile. These patterns of missingness were identical between the MAR and MNAR mechanisms, the only difference being that SI and RNAseqCovarImpute had access to these variables (while imputing data) under MAR, while these variables were masked under MNAR. Thus, under MNAR, unobserved data influenced the patterns of missingness. When data were simulated to be missing completely at random (MCAR), missingness did not depend on alcohol use, family income, or any other covariate. For example, in the 10 simulated datasets where 55% of individuals had at least one missing data point, the rate of individuals with at least one missing data point was 55% among alcohol users, 53% among those reporting no alcohol use, 56% among those in the bottom quartile of family income, and 54% in the top quartile of family income.

In differential expression analysis using the ECHO-PATHWAYS dataset, RNAseqCovarImpute was the best performer, with the highest TPR, lowest FPR, and lowest mean absolute percentage error (MAPE) across most scenarios, especially with increasing levels of missing data (Fig.  2 ). For example, when 55% of participants had at least one missing data point, the TPR ranged from 0.713 to 0.994 for RNAseqCovarImpute, from 0.214 to 0.977 for SI, and from 0.006 to 0.391 for CC (Fig.  2 A). FPR was well-controlled under 0.05 in most scenarios, but more consistently so for RNAseqCovarImpute. For example, the median FPR was always < 0.05 for RNAseqCovarImpute, while there were some cases of high FPRs for the CC method when data were MCAR, and for the SI method when data were MNAR (Fig.  2 B). MAPE was lower for RNAseqCovarImpute in almost every scenario (Fig.  2 C).

Performance of missing data methods on ECHO-PATHWAYS dataset. A True positive rate (TPR), B false positive rate (FPR), and C mean absolute percentage error (MAPE) shown for complete case (CC), single imputation (SI), and RNAseqCovarImpute multiple imputation differential expression analyses on ten datasets with simulated missingness per missingness mechanism per level of missingness. Box (median and interquartile range) and whiskers (1.5* interquartile range) shown along with one point per simulation. Dashed line at target FPR of 0.05

The NSCLC dataset included 12,353 genes after filtering, of which 5718 were significantly associated with sex in the full data model (true positives) while adjusting for covariates. After inducing missingness in the covariate data, RNAseqCovarImpute was the best performer with the highest TPR, lowest FPR, and lowest MAPE across most scenarios, especially with increasing levels of missing data (Fig.  3 ). For example, when 85% of participants had at least one missing data point, the TPR ranged from 0.933 to 0.987 for RNAseqCovarImpute, from 0.902 to 0.984 for SI, and from 0.296 to 0.604 for CC (Fig.  3 A). Many scenarios had FPR > 0.05 for CC, while FPR was well-controlled at approximately 0.05 for SI, and consistently below 0.05 for RNAseqCovarImpute (Fig.  3 B). As with FPR, MAPE was lowest for RNAseqCovarImpute, followed by SI and CC, respectively (Fig.  3 C).

Performance of missing data methods on NSCLC dataset. A True positive rate (TPR), B false positive rate (FPR), and C mean absolute percentage error (MAPE) shown for complete case (CC), single imputation (SI), and RNAseqCovarImpute multiple imputation differential expression analyses on ten datasets with simulated missingness per missingness mechanism per level of missingness. Box (median and interquartile range) and whiskers (1.5* interquartile range) shown along with one point per simulation. Dashed line at target FPR of 0.05

The EBV dataset included 8677 genes after filtering, of which 7449 were significantly associated with time in the full data model (true positives) while adjusting for covariates. As with the datasets above, after inducing missingness in the covariate data, RNAseqCovarImpute was the best performer with the highest TPR, lowest FPR, and lowest MAPE across most scenarios (Fig.  4 ).

Performance of missing data methods on EBV dataset. A True positive rate (TPR), B false positive rate (FPR), and C mean absolute percentage error (MAPE) shown for complete case (CC), single imputation (SI), and RNAseqCovarImpute multiple imputation differential expression analyses on ten datasets with simulated missingness per missingness mechanism per level of missingness. Box (median and interquartile range) and whiskers (1.5* interquartile range) shown along with one point per simulation. Dashed line at target FPR of 0.05

In addition to the real RNA-sequencing datasets above, four sets of synthetic RNA-sequencing data were used to compare performances of RNAseqCovarImpute, SI, and CC differential expression analysis. The NSCLC RNA-sequencing data were modified to add known signal using the seqgendiff package [ 18 ] (“  Methods ”). Compared with fully synthetic count data from theoretical distributions, this method better reflects realistic variability in RNA-sequencing data. Subsets of 25–99% of genes were randomly selected to have their coefficient of association (Log2 fold-changes) with sex set to zero. Distributions of gene expression coefficients associated with sex depended on the desired null gene rates for each synthetic dataset, but followed a similar form compared with the original NSCLC data as intended (Additional file 1: Fig. S5). Coefficients for the remaining genes were drawn randomly from a gamma distribution, and an additional diagnostic confirmed that the coefficients for each gene estimated from the limma-voom pipeline on the synthetic count tables closely matched these pre-defined coefficients input into the seqgendiff package (Additional file 1: Fig. S6). Applied to these synthetic RNA-sequencing datasets, RNAseqCovarImpute had higher TPRs (Additional file 1: Fig. S7) and lower FPRs (Additional file 1: Fig. S8) compared to CC and SI differential expression analysis across most scenarios. Moreover, the advantages of RNAseqCovarImpute were most apparent for synthetic datasets with weaker signals. For example, all methods had FPRs < 0.05 for the synthetic data with the strongest signal (i.e., 75% of genes associated with the predictor of interest and only 25% null genes). However, with 99% null genes and only 1% of genes modified to correlate with the predictor of interest, RNAseqCovarImpute maintained FPRs < 0.05 while the other methods did not (Additional file 1: Fig. S8).

Overall, RNAseqCovarImpute outperformed SI and CC methods in differential expression analysis by achieving higher TPRs, lower FPRs, and lower MAPEs across various real-world and synthetic RNA-sequencing datasets. Its advantages were most notable, especially with respect to controlling FPRs, in scenarios with high levels of missing data or predictors of interest that are only weakly associated with the RNA-sequencing data.

Computational benchmarks

Methods were benchmarked in an analysis of the ECHO-PATHWAYS dataset with 14,026 genes, 994 observations, 4 covariates in the model, and 55% missingness under MCAR on a Windows machine with 3.8 GHz processing speed and 16 GB random-access memory. MI methods were assessed with 10 imputed datasets. Over three iterations per method, memory allocations and median run times were 16.6 GB and 13.52 min for the RNAseqCovarImpute MI Gene Bin method, 4.32 GB and 2.68 min for the RNAseqCovarImpute MI PCA method, 7.58 GB and 17.46 s for SI, and 3.23 GB and 6.71 s for CC. Computation time was further assessed for the RNAseqCovarImpute MI PCA method over several combinations of sample size, number of genes, and number of imputed datasets (Additional file 1: Fig. S9).

Application of RNAseqCovarImpute in analysis of maternal age and placental transcriptome

In a real-world example, RNAseqCovarImpute was applied to the largest placental transcriptomic dataset to-date, which was generated by the ECHO prenatal and early childhood pathways to health (ECHO-PATHWAYS) consortium [ 5 ]. This analysis examined the association of maternal age with the placental transcriptome while adjusting for race, ethnicity, family income, maternal education, tobacco and alcohol use during pregnancy, delivery method, study site, fetal sex, and sequencing batch. The causal relationships among these variables are illustrated in Fig.  5 .

Maternal age and placental transcriptome conceptual model. Conceptual model of association between maternal age (predictor) and the placental transcriptome (outcome). Confounders are upstream causes of both the predictor and outcome. Mediators are on the causal pathway between the predictor and outcome. Precision variables could affect the outcome but have no clear casual effect on the predictor

Among 1045 individuals included in this analysis, 6% (61) were missing data for at least one of the 10 covariates, mostly driven by 4% (41) of individuals missing family income data. There were no missing data for delivery method, study site, fetal sex, and sequencing batch, and a minimally adjusted analysis including these variables identified 1071 differentially expressed genes (DEGs) significantly associated with maternal age. Adjusting for all covariates resulted in fewer maternal age DEGs: in the CC, SI, and RNAseqCovarImpute MI analyses, maternal age was associated with 575, 214, and 399 DEGs, respectively (Fig.  6 A). The CC and SI analyses uncovered 91% (362) and 54% (214) of the significant DEGs from the MI method, respectively, while there were 32 DEGs exclusive to MI (Fig.  6 A). Additionally, CC analysis was repeated while omitting the family income covariate, which preserved sample size while allowing possible confounding by this variable. This analysis uncovered 334 DEGs, of which 68% (270) overlapped with the DEGs from the MI method (Additional file 1: Fig. S10). Although there were some differences, genes ranked from lowest to highest P value followed similar orders between the methods (Fig.  6 B). The most substantial differences compared with the P value rank order from the MI analysis were observed in the fully adjusted CC and CC omitting family income analyses (Fig.  6 B). Imputation diagnostics for family income following the RNAseqCovarImpute MI method indicated good convergence and reasonable imputed values (Additional file 1: Fig. S11).

Maternal age and the placental transcriptome differential expression analysis. Venn diagram depicts shared and distinct differentially expressed genes for each method ( A ). P value rankings for each method for the top 10 genes with the lowest P values from the multiple imputation analysis ( B ). Volcano plots of maternal age associations with placental gene expression in complete case ( C ), single imputation ( D ), and multiple imputation ( E ) analyses. “Drop Income” indicates complete case analysis excluding the income covariate ( F ). Models include the following covariates: maternal race, ethnicity, education, tobacco and alcohol use during pregnancy, household income adjusted for region and inflation, delivery method, fetal sex, sequencing batch, and study site. Log 2 -adjusted fold-changes (LogFCs) shown for each 1 year increase in maternal age. Horizontal and vertical lines at P  = 0.05 and LogFC ± 0.04, respectively. HGNC gene symbols shown for significant genes with false discovery rate adjusted P value ( P -adj) < 0.05 and LogFC beyond 0.04 cutoff

Many of the top DEGs in the MI analysis, according to their significance and fold-change magnitude (Fig.  6 C–F), play roles in inflammatory processes and the immune response. S100A12 and S100A8 are pro-inflammatory calcium-, zinc-, and copper-binding proteins, CXCL8 (IL-8) and IL1R2 are pro-inflammatory cytokines/cytokine receptors, SAA1 and CASC19 are known to be expressed in response to inflammation, while LILRA5 , a leukocyte receptor gene, may play a role in triggering innate immune responses [ 19 ].

Pathway enrichment of the MI differential expression results revealed 32 Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways that were downregulated in association with older maternal age (Fig.  7 ). Among these downregulated KEGG pathways, 11 belong to the immune system KEGG group and 6 belong to the signal transduction group. Antigen processing and presentation, an immune system KEGG pathway, was the most strongly downregulated pathway according to its enrichment effect size and P value (Fig.  7 ).

Maternal age and the placental transcriptome pathway analysis. T -statistics (Log2FCs divided by standard error) from the differential expression analyses of maternal age were input into pathway analysis for Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways (excluding KEGG human disease pathways) using the generally applicable gene set enrichment (GAGE) method. Mean t -statistic of all genes in each KEGG pathway shown with corresponding P value from GAGE (larger points indicate smaller P values)

Application of RNAseqCovarImpute in analysis of colorectal carcinoma and the blood platelet transcriptome

In another real-world example, RNAseqCovarImpute was applied to a dataset of blood platelet RNA-sequencing from 42 individuals with colorectal carcinoma and 59 healthy donors [ 20 ]. This dataset included 3227 genes after filtering. There were 14 individuals with KRAS mutant tumors and 2 individuals with PIK3CA mutant tumors compared with 85 wild-type individuals. No data were missing for cancer status or genotype, while 34% (34) were missing data for sex, and 40% (40) were missing data for age. In the CC, SI, and RNAseqCovarImpute MI analyses, colorectal carcinoma was associated with 2491, 2403, and 2579 DEGs, respectively, while controlling for genotype, sex, and age (Additional file 1: Fig. S12A). The CC and SI analyses uncovered 94% (2422) and 92% (2360) of the significant DEGs from the MI method, respectively, while there were 98 DEGs exclusive to MI (Additional file 1: Fig. S12A). Genes ranked from lowest to highest P value followed similar orders between the methods (Additional file 1: Fig. S12B).

Many of the top DEGs in the MI analysis, according to their significance and fold-change magnitude (Additional file 1: Fig. S12C–E), have been previously shown to play roles in cancer etiology. For example, colorectal carcinoma was associated with the downregulation of GK5. Genes involved in glycerol metabolism, including GK5 , have been previously implicated in the etiology of cancers, including colorectal carcinoma [ 21 , 22 , 23 , 24 ]. Mutations in MDN1 , which was downregulated in association with colorectal cancer here, have been shown to correlate with elevated tumor mutation rates in breast and colorectal cancers [ 25 , 26 ]. Downregulation of TNFRSF1B (a member of the tumor necrosis factor gene family) in association with colorectal cancer here is consistent with prior studies showing lower mRNA expression of TNFRSF1B in lung cancer compared with normal lung tissue [ 27 ].

We have shown that a MI procedure that includes PCA of the gene expression data in the imputation predictor matrix has a performance advantage relative to CC and SI methods in RNA-sequencing studies using the limma-voom pipeline. We found that our newly implemented MI method in RNAseqCovarImpute was the best performer with higher TPRs and lower FPRs and MAPEs across a wide range of missing data scenarios.

Similar methods allowing for the inclusion of high dimensional outcome data in MI models have been developed for epigenome wide association studies (EWAS) [ 8 , 9 ]. In EWAS, there appear to be tradeoffs between CC analysis and MI, with MI identifying more true positives but also more false positives [ 8 ]. In the simulations presented here, however, RNAseqCovarImpute identified more true DEGs with no false positive tradeoff. The application of MI to EWAS studies represents a more challenging problem owing to higher dimensionality of the methylome (850,000 CpG sites with Illumina’s EPIC array [ 28 ]) versus the transcriptome (typically tens of thousands of genes). The application of MI to EWAS studies might benefit from employing a PCA-based approach similar to the one used here. Moreover, future methods development could also tackle the additional challenges in applying MI to alternative epigenomic and transcriptomic methods such as differentially methylated region and pathway enrichment (discussed below) analyses.

To address the sparsity of single-cell RNA-sequencing data, imputation methods to fill in missing or zero RNA-sequencing counts have been extensively developed [ 29 ]. Little attention has been paid, however, to the imputation of missing covariate data in studies where gene expression is the outcome of interest. Methods for the treatment of missing data are well-established in observational epidemiology [ 30 ], with MI increasingly the method-of-choice [ 31 , 32 ]. Yet human observational studies of gene expression have often failed to report on the treatment of missing data, despite its prevalence. When missing data are explicitly addressed in this context, researchers typically utilize CC analyses [ 33 , 34 , 35 ], while SI is a less common alternative [ 6 ]. Despite its advantages, we are unaware of any studies with transcriptomic outcomes that have utilized MI for missing covariate data. The simulations presented here suggest that future observational transcriptomic studies may benefit from employing MI via RNAseqCovarImpute over CC or SI. Moreover, we developed an R package so that users may easily apply the methods presented here to their own data.

We applied RNAseqCovarImpute to a large observational study of maternal age and the placental transcriptome. This analysis assessed the association of maternal age with placental gene expression controlling for confounding variables such as maternal race, ethnicity, and socioeconomic status, and potential mediators such as alcohol and tobacco use during pregnancy. Although there was some overlap, the MI analysis uncovered a different set of differentially expressed genes compared with the CC and SI analyses. CC analysis uncovered a larger number of DEGs compared with MI, possibly indicating that CC may have higher power in some cases. However, the simulations suggest that CC analyses have higher FPRs across many scenarios compared with MI via RNAseqCovarImpute. Individuals with missing data could systematically differ from those with complete data, and dropping these individuals could result in bias. Although higher power of CC remains a possibility, it is more likely that the excess number of DEGs in the CC analysis could be explained by false positives owing to such bias. Ultimately, in a real-world example, the method for dealing with missing data matters, and our simulations suggest that MI should be the preferred approach.

Nevertheless, any of these missing data methods would be a better alternative than omitting covariate control entirely, a common albeit unsatisfactory approach in observational transcriptomic studies. Another reasonable alternative is to perform CC analysis while omitting variables with the most missing data. Compared with fully adjusted CC analysis, CC while omitting the family income variable was more similar to the MI analysis in terms of the total number of DEGs, but displayed more differences in terms of the P value rank order of DEGs. Researchers may also opt to only include covariates with complete data, which preserves sample size and avoids the need for imputation but may introduce bias due to uncontrolled variables. For the ECHO-PATHWAYS dataset, only including covariates with complete data resulted in a minimal model adjusting for delivery method, study site, fetal sex, and sequencing batch. This reduced model identified a much larger 1071 DEGs significantly associated with maternal age compared with 214–575 DEGs in the CC, SI, and RNAseqCovarImpute MI analyses adjusting for all covariates. This larger number of DEGs was likely due to confounding by race, ethnicity, lifestyle, and socioeconomic status variables that were not controlled in this analysis. Failure to control for these variables in analyses of maternal age could lead to erroneous conclusions and even faulty clinical recommendations. For instance, studies have shown that the positive associations of young maternal age with child ADHD in unadjusted analyses are eliminated or even reversed following adjustment for confounding and mediating variables [ 36 , 37 , 38 ]. Thus, younger pregnancies do not confer increased ADHD risk because of the biology of aging per se but owing to other variables that are correlated with maternal age. Younger mothers are more likely to smoke during pregnancy, and prenatal tobacco exposure may impair neurodevelopment. If the link between younger pregnancy and adverse child development is mediated by increased tobacco exposure, then clinical efforts focusing on reducing tobacco exposures during pregnancy would be more effective than recommendations regarding the ideal age for childbearing [ 36 ].

Advanced maternal age is a well-known risk factor for preterm birth [ 39 , 40 ]. These analyses demonstrated associations of advanced maternal age with downregulation of individual genes (i.e., CXCL8 ) and pathways (i.e., 9 immune system and 4 signal transduction pathways) that were also downregulated in association with spontaneous preterm birth in a prior analysis [ 41 ]. Future studies should formally explore these overlapping results as putative mechanistic links between advanced maternal age and preterm birth.

To the best of our knowledge, MI via RNAseqCovarImpute is applicable to any RNA-sequencing study that has missing values in the paired covariate data. In addition to the placental transcriptomics data in ECHO-PATHWAYS, we applied RNAseqCovarImpute to three different datasets. In one example, we analyzed blood platelet RNA-sequencing data from individuals with colorectal carcinoma and healthy controls [ 20 ]. This analysis uncovered several differentially expressed genes with known roles in the etiology and progression of various cancers, including colorectal carcinoma. Future studies may utilize RNAseqCovarImpute to achieve higher power and lower FPRs in differential gene expression analyses of a wide range of factors and across diverse tissue types.

One limitation to RNAseqCovarImpute is that it is dependent on selection of a number of PCs to integrate, and the user will need to define the optimal number of PCs to retain using established methods such as Horn’s parallel analysis or a variance explained cutoff. Our testing suggests that several popular methods perform well when missing data is minimal. At high levels of missing data, Horn’s parallel analysis was the best general method of choice, but performance could vary with different datasets. Another drawback to RNAseqCovarImpute is that its compatibility with pathway and gene set enrichment methods is currently limited, as many of these methods were developed without MI in mind. The RNAseqCovarImpute MI method produces one final list of genes with their associated t -statistics, log fold changes, and P values for differential expression. Thus, the method is compatible with gene set enrichment analyses that utilize gene rankings such as overrepresentation analysis, or gene level statistics such as camera [ 42 ] and GAGE (utilized here in the maternal age analysis) [ 43 ]. However, the final gene list produced by RNAseqCovarImpute is based on the combined analyses of the MI datasets. Although theoretically possible, methods that require as input a gene expression matrix or data at the individual sample level are likely not out-of-box compatible with RNAseqCovarImpute. Future work could moderate such methods to accommodate analysis of multiply imputed RNA-sequencing data. Additionally, the RNAseqCovarImpute package is also not out-of-box compatible with all differential expression analysis methods, as it was designed to utilize the limma-voom pipeline. Another limitation was that, as an MI method, RNAseqCovarImpute required more processing time compared with CC or SI. Finally, data imputation is a rapidly evolving field, and emerging machine learning SI and MI methods [ 44 ] should be tested in the context of RNA-sequencing in future studies.

Conclusions

As the cost of sequencing decreases, studies of the transcriptome may experience a substantial shift from small-scale in vitro and in vivo experimental systems to larger-scale clinical and epidemiologic contexts where missing covariate data is prevalent. MI is a well-established method to handle missing covariate data in epidemiology, but was previously not compatible with transcriptomic outcome data. We developed an R package, RNAseqCovarImpute, to integrate limma-voom RNA-sequencing analysis with MI for missing covariate data, and demonstrated that this method has superior performance compared with SI and CC analyses. Ultimately, RNAseqCovarImpute represents a promising step towards harmonizing transcriptomic and epidemiologic approaches by addressing the critical need to accommodate missing covariate data in RNA-sequencing studies. Future studies may expand upon the MI methods developed here for RNA-sequencing to address problems associated with missing covariate data in other settings, including DNA methylation, proteomics, metabolomics, and other high dimensional data types.

RNAseqCovarImpute multiple imputation principal component analysis (MI PCA) method

A graphical overview of the RNAseqCovarImpute MI PCA method is shown in Fig.  1 , and the corresponding R code are available on GitHub and Bioconductor (see Availability of data and materials).

Filtering genes with low counts

A common filtering cutoff in RNA-sequencing is around 10 counts per gene, and filtering on log-counts per million (logCPM) values rather than raw counts is recommended to avoid giving preference to samples with large library sizes [ 45 , 46 ]. The filtering cutoff on the CPM scale is roughly equal to the count cutoff of 10 divided by the minimum library size in millions. Here, we filter to keep genes with an average CPM across all samples above this cutoff reflecting approximately 10 counts per gene.

Data normalization

Following RNA-sequencing and mapping of reads to each gene or probe, an RNA-sequencing dataset consists of a matrix of counts for genes g  = 1 to the total number of genes G , where counts are recorded for all samples i  = 1 to the total number of samples n . The library size R i , which is the total number of reads for a given sample, is expressed as:

The library size R i is additionally scale-normalized using the weighted trimmed mean of M-values (TMM) method [ 47 ], and logCPMs normalized to library size are computed, offsetting the counts by 0.5 to avoid taking the log of zero and offsetting the library size by 1:

Principal component analysis (PCA)

Fitting an imputation model where the number of independent variables is far greater than the number of individuals in the study is generally not feasible. In RNA-sequencing studies with tens of thousands of genes, we can surmount this problem by reducing the dimensionality of the gene expression data with PCA and including a subset of PCs in the MI prediction models.

For the MI PCA method, we conduct PCA using Bioconductor’s PCAtools R package [ 13 ] on the gene expression data normalized as described above. There is no universally optimal approach to selecting the number of PCs to retain in PCA. Horn’s parallel analysis retains PCs with eigenvalues greater than eigenvalues of random data [ 14 , 15 ] and is regarded as one of the best empirical methods to determine component retention in PCA [ 48 ]. Performance of MI PCA was compared when using Horn’s parallel analysis, an 80% variance explained cutoff, and the elbow method, where all PCs are retained that come before the elbow point in the curve of variance explained by each successive PC. Methods for determining the number of retained PCs were implemented using Bioconductor’s PCAtools R package [ 13 ].

Data imputation

The retained PCs are added to the covariate data and utilized along with all covariates in the MI prediction model when creating m multiply imputed datasets. Data are imputed using the “mice” R package with its default predictive modeling methods, which are predictive mean matching, logistic regression, polytomous regression, and proportional odds modeling for continuous, binary, categorical, and unordered variables, respectively [ 49 ].

• Differential expression analysis

The limma-voom pipeline is run on each m imputed dataset separately. This procedure fits weighted linear models for each gene that take into account individual-level precision weights based on the mean–variance trend [ 10 ]. A linear model is fit by ordinary least squares separately for each gene. The model includes an intercept \({\beta }_{0}\) , and coefficients \({\beta }_{1}\) – \({\beta }_{n}\) for any number of covariates \({C}_{1}\) – \({C}_{n}\) .

The geometric mean of the library sizes plus one,  \(\widetilde R\)  is computed. The average logCPM for each gene,  \(\overline{\log CPM_g}\) is computed and converted to an average log-count by:

The regressions provide fitted logCPM values, \({\widehat{\mu }}_{gi}\) for each gene ( g ) and each sample ( i ) that are converted to fitted counts by:

A LOWESS curve is fitted to the square root of the residual standard deviations from the regression models as a function of \(\widetilde{r}\) , the average log-counts. Interpolating the curve on the interval of library sizes \(\widetilde{R}\) defines the piecewise linear function lo() for predicting individual observation-level square-root standard deviations. The predicted square-root standard deviation of individual logCPM observations \({logCPM}_{gi}\) is equal to lo( \({\widehat{\lambda }}_{gi}\) ). Voom precision weights are defined as the predicted inverse variances, lo( \({\widehat{\lambda }}_{gi}\) ) −4 .

Voom precision weights and logCPM values are input into the limma linear modeling framework which utilizes an empirical Bayes procedure to squeeze gene-wise variances towards a common value [ 11 , 12 ]. This procedure is run separately on each m set of imputed data to obtain coefficients and standard errors for each gene.

Pooling results

Rubin’s rules [ 2 ] are used to pool coefficients and standard errors, and the Barnard and Rubin adjusted degrees of freedom is calculated [ 50 ] (see [ 3 ] for more details). From the limma-voom pipeline above, the linear regression coefficient ( \(\beta\) ) and the Bayesian moderated standard error ( SE ) for each gene from each m number of models on the m number of imputed datasets is extracted. The Bayesian moderated degrees of freedom ( df ) are averaged across the m models. One gene at a time, results are pooled across the m models as follows.

Coefficients are pooled with the basic formula of taking the mean.

Within imputation variance ( V W ) is the average of the sum of the squared standard errors ( SE s) divided by m .

Between imputation variance ( V B ) reflects extra variance due to missing data and is expected to be large when missing data is high. It is calculated as the sum of the squared differences between the pooled coefficient ( \(\overline{\beta }\) ) and each coefficient ( \({\beta }_{i}\) ) from each imputed dataset divided by m  − 1.

Total variance ( V Total ) is calculated and its square root as the pooled standard error ( SE Pooled ).

The pooled coefficient ( \(\overline{\beta }\) ) divided by the pooled standard error ( SE Pooled ) is defined as the t -statistic ( t ) for significance testing.

The degrees of freedom for significance testing also needs adjustment. First calculate lambda , the proportion of total variance due to missingness.

An older version of the degrees of freedom ( df Old ) proposed in Rubin (1987) is adjusted using the equations from Barnard and Rubin (1999). This MI adjusted degrees of freedom ( df Adjusted ) is the same degrees of freedom used in the “mice” R package.

P values are derived from the t -distribution. In R, 2-sided P values can be calculated using the pt function, which returns the area for the Student’s t -distribution to the left of the t -statistic for a given degrees of freedom. In R:

After this pooling procedure is completed for every gene, P values for the linear model contrast of interest are adjusted for false-discovery-rate control [ 51 ].

Performance on three example datasets

Performance was evaluated in a simulation study using three real RNA-sequencing and covariate datasets and four synthetic sets of RNA-sequencing data (described below). Performance was compared between SI followed by the standard limma-voom differential expression analysis, CC limma-voom differential expression analysis, and the two RNAseqCovarImpute methods, MI Gene Bin (Additional file 1: Supplemental Methods) and MI PCA (described above).

Determining true differentially expressed genes (DEGs)

Differential expression analysis using the limma-voom pipeline was conducted on the entire set of observations with their complete covariate data (hereinafter “full data”). These models estimated the effect of a predictor of interest on gene expression while controlling for several covariates. Genes significantly associated with the predictor of interest at FDR < 0.05 in these full data models were defined as true DEGs.

Simulating missing data under different missingness mechanisms

Missingness was simulated using the ampute function from the “mice” package [ 49 ]. Missingness was simulated to emulate a common situation in scientific research where an investigator has complete data for a predictor of interest, but may have missing data for other important covariates. Therefore, missingness was only induced in adjustment covariates and not the predictor of interest. We explored scenarios with various levels of missing data ranging from 5 to 85% of participants having at least one missing data point, and under three missingness mechanisms: missing completely at random (MCAR), missing at random (MAR), and missing not at random (MNAR). We simulated ten datasets for each missingness mechanism at each level of missingness before applying the SI, CC, MI, and MI PCA methods and comparing the results with the full data model.

One or two covariates (described in detail below for each dataset) were defined as MNAR variables: these variables were not included as adjustment covariates in the differential expression analysis, but had influence in determining the missingness in the other covariate data. Under the MAR mechanism, the data that explain the missingness are all available. Thus, for the MAR mechanism, the SI, MI, and MI PCA methods had access to these MNAR variables while imputing missing covariate data. Under the MNAR mechanism, patterns of missingness in the data are related to unobserved or unmeasured factors. Thus, for the MNAR mechanism, the SI, MI, and MI PCA methods did not have access to these MNAR variables while imputing missing covariate data. Under the MCAR mechanism, missingness in the data are completely random and do not depend on values of the covariates.

CC analyses dropped any individual with at least one missing data point, while SI imputed missing data using the missForest package [ 52 ]. The limma-voom pipeline was applied for CC and SI as described for the full data model.

Evaluating results

Our objective was to evaluate the ability of the SI, CC, MI, and MI PCA methods to identify true DEGs from the full data model as significant while limiting false positives. True DEGs from the full data model that were also identified as significant by a given method were defined as true positives. We report the true positive rate (TPR) as the proportion of true DEGs identified as significant for each method out of the total number of true DEGs from the full data model. Genes erroneously identified as significant by a given method that were not true DEGs from the full data analysis were defined as false positives. We report the false positive rate (FPR) as the proportion of false positives out of the total number of significant results for each method. We report the mean absolute percentage error ( MAPE ) across all true DEGs to characterize the ability of each method to reproduce gene expression coefficients from the full data model, where \({\beta }_{truth g}\) is defined as the true coefficient from a DEG in the full data model, and \({\beta }_{g}\) is defined as the coefficient for the same gene estimated using SI, CC, MI, or MI PCA following simulated missingness. MAPE was calculated as:

Three RNA-sequencing datasets with mapped reads were obtained and processed as described above in “  Data normalization ” and “  Filtering genes with low counts .” The first dataset was based on placental RNA-sequencing and covariate data from the ECHO prenatal and early childhood pathways to health (ECHO-PATHWAYS) consortium [ 5 ]. This study harmonized extant data from three pregnancy cohorts from diverse populations across the country. The consortium’s core aim is to explore the impact of chemical exposures and psychosocial stressors experienced by the mother during pregnancy on child development, and to assess potential underlying placental mechanisms. To investigate placental mechanisms, the study generated RNA-sequencing data for the CANDLE and GAPPS pregnancy cohort samples. All participants of the CANDLE and GAPPS studies provided informed consent upon enrollment and research protocols were approved by the Institutional Review Boards (IRBs) at the University of Tennessee Health Science Center (IRB approval: 17–05154-XP) as well as the Seattle Children’s Hospital (IRB approval: STUDY00000608) and the University of Washington (IRB approval: STUDY00000638). The generation of placental RNA-sequencing data for this study is described elsewhere [ 41 ]. Among the enrolled study sample of 1503, transcriptomic data are available for 1083 individuals. We excluded 18 placental abruptions and 20 individuals missing maternal age data, leaving a sample of 1045. We retained only protein-coding genes, processed pseudogenes, and lncRNAs.

Covariates from the ECHO-PATHWAYS dataset included in the simulation study were maternal age (continuous), child sex (male versus female), RNA-sequencing batch, maternal tobacco use during pregnancy (yes versus no), maternal alcohol use during pregnancy (yes versus no), and family income (continuous). The full data model restricted to 994 individuals with complete data for these variables. Mothers self-reported alcohol use, while the positive tobacco exposure group included individuals with maternal urine cotinine above 200 ng/mL [ 53 ], as well as individuals who were below this cutoff but self-reported tobacco use during pregnancy. Maternal age was defined as the predictor of interest, while sex, prenatal tobacco exposure, and RNA-sequencing batch were modeled as covariates. Simulated missing data ranged from 5 to 55% of participants having at least one missing data point. Maternal alcohol use and family income served as MNAR variables. Levels of missingness according to different values of these MNAR variables were summarized to illustrate differences between MAR, MNAR, and MCAR missingness mechanisms.

Two additional datasets were selected based on their large sample sizes, public availability, and ample number of covariates that could be examined in covariate imputation analyses. The non-small cell lung cancer (NSCLC) dataset was downloaded from the European Molecular Biology Laboratory—European Bioinformatics Institute (EMBL-EBI: E-GEOD-81089) and is based on [ 16 ]. For the NSCLC dataset ( N  = 670), the association of sex (male versus female) with the transcriptome was examined, adjusting for participant age (continuous) and participant smoking status (smoker versus ex-smoker versus non-smoker). Sampling site (tumor versus non-malignant) served as an MNAR variable. The Epstein-Barr virus (EBV) dataset was downloaded from EMBL-EBI (E-MTAB-7805) and is based on [ 17 ]. For the EBV dataset ( N  = 384), the association of time (continuous days) with the transcriptome was examined, adjusting for infection status (EBV infected versus not infected). Donor source (categorical, three individuals) served as an MNAR variable. All methods performed better at recovering the full data model results for the EMBL-EBI datasets compared with the ECHO-PATHWAYS dataset, so analyses with these datasets examined 55–85% of participants having at least one missing data point.

Finally, four sets of synthetic RNA-sequencing data were also used to compare performances of RNAseqCovarImpute (MI PCA Horn method), SI, and CC differential expression analysis. The NSCLC RNA-sequencing data were modified to add known signal using the seqgendiff package [ 18 ]. The method relies on binomial thinning of the RNA-sequencing count matrix to closely match user defined coefficients. Rather than generating counts from theoretical distributions, thinning a real set of RNA-sequencing counts can better preserve realistic variability and inter-gene correlations typical of RNA-sequencing data [ 18 ]. Subsets of 25%, 50%, 75%, or 99% of genes were randomly selected to have their coefficient of association (Log2 fold-changes) with sex set to zero. The remaining coefficients were drawn randomly from a gamma distribution generated using rgamma(shape = 1) from the stats package in R.

Application of RNAseqCovarImpute in analysis of maternal age and the placental transcriptome

This analysis examined the association of maternal age with the placental transcriptome while controlling for 10 covariates using the ECHO-PATHWAYS sample described above ( N  = 1045). Covariates included family income adjusted for region and inflation (USD), maternal race (Black vs. other), maternal ethnicity (Hispanic/Latino vs. not Hispanic/Latino), maternal education (< high school vs. high school completion vs. college or technical school vs. graduate/professional degree), study site, maternal alcohol during pregnancy (yes vs. no), maternal tobacco during pregnancy (yes vs. no), delivery method (vaginal vs. C-section), fetal sex (male vs. female), and RNA-sequencing batch. The causal relationships among these variables are illustrated in Fig.  5 . For the maternal race variable, American Indian/Alaska Native, multiple race, and other were collapsed along with White participants to avoid small or zero cell sizes in multivariable models. Only protein-coding genes, processed pseudogenes, and lncRNAs, and genes with average log-CPM > 0 (approximately 10 counts for this dataset) were retained, resulting in a final sample of 14,029 genes. DEGs associated with maternal age while adjusting for all 10 covariates were compared between the CC, SI, and RNAseqCovarImpute MI PCA methods. To retain the entire sample size without covariate imputation, a reduced model was fit by omitting any covariates with missing data. Additionally, an alternative CC analysis was performed while omitting family income, the variable with the most missing data.

T -statistics (Log2FCs divided by standard error) from the differential expression analyses were input into pathway analysis for Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways (excluding KEGG human disease pathways) using the generally applicable gene set enrichment (GAGE) method [ 43 ]. For pathways with GAGE FDR < 0.05, GAGE P values and the mean differential expression t -statistic for all genes in the pathway were plotted.

In another real-world example, RNAseqCovarImpute was applied to a dataset of blood platelet RNA-sequencing from 42 individuals with colorectal carcinoma and 59 healthy donors (EMBL-EBI: E-GEOD-68086) [ 20 ]. This analysis examined the association of colorectal carcinoma versus healthy cancer status with the transcriptome while controlling for genotype ( KRAS vs. PIK3CA vs. wild-type), sex, and age ( N  = 101). DEGs associated with colorectal carcinoma while adjusting for these covariates were compared between the CC, SI, and RNAseqCovarImpute MI PCA methods.

Availability of data and materials

The RNAseqCovarImpute R package is available at the Bioconductor repository under the GNU General Public License v3.0 ( https://doi.org/10.18129/B9.bioc.RNAseqCovarImpute ) [ 54 ]. Source code for simulating missing covariate data and evaluating different methods for handling missing data, including the complete case, single imputation, and RNAseqCovarImpute methods, is available at the Zenodo repository under the GNU General Public License v3.0 ( https://doi.org/10.5281/zenodo.13314514 ) [ 55 ]. The NSCLC data are available at EMBL-EBI accession E-GEOD-81089 [ 16 ]. The EBV data are available at EMBL-EBI accession E-MTAB-7805 [ 17 ]. The colorectal carcinoma data are available at EMBL-EBI accession E-GEOD-68086 [ 20 ]. The ECHO-PATHWAYS RNA-sequencing data are available at dbGaP study accessions phs003619.v1.p1 and phs003620.v1.p1. The ECHO-PATHWAYS covariate data are available upon reasonable request following the data sharing guidelines of the ECHO-PATHWAYS consortium, outlined in LeWinn et al. [ 5 ].

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Acknowledgements

The authors would like to thank the study staff, data teams, and co-investigators involved in the CANDLE and GAPPS cohorts as well as the ECHO-PATHWAYS consortium for their invaluable contributions to the ECHO-PATHWAYS dataset. We are also grateful to the study participants who generously volunteered their time for this study. We additionally thank the researchers and participants contributing to the publicly available NSCLC and EBV data utilized here. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. This manuscript has been reviewed by PATHWAYS for scientific content and consistency of data interpretation with previous PATHWAYS publications.

Peer review information

Andrew Cosgrove was the primary editor of this article and managed its editorial process and peer review in collaboration with the rest of the editorial team.

Review history

The review history is available as Additional file 2.

ECHO PATHWAYS is funded by the National Institutes of Health (NIH; 1UG3OD023271-01, 4UH3OD023271-03). The generation of RNA-sequencing data for this study was supported by the University of Washington Interdisciplinary Center for Exposures, Diseases, Genomics, and Environment funded by the National Institute of Environmental Health Sciences (NIEHS; 2P30ES007033). This research was conducted using specimens and data collected from the Conditions Affecting Neurocognitive Development and Learning in Early Childhood (CANDLE) study which was funded by the Urban Child Institute. This research was conducted using specimens and data collected and stored on behalf of the Global Alliance to Prevent Prematurity and Stillbirth (GAPPS) Repository. BB was supported by the UW NIEHS sponsored Biostatistics, Epidemiologic and Bioinformatic Training in Environmental Health (BEBTEH) Training Grant: NIEHS T32ES015459. AP was supported by NICHD K99/R00HD096112 and 1R01ES033785.

Author information

Adam A. Szpiro, James W. MacDonald, and Alison G. Paquette contributed equally to this work.

Authors and Affiliations

Department of Environmental and Occupational Health Sciences, University of Washington, Seattle, WA, USA

Brennan H. Baker, Sheela Sathyanarayana, James W. MacDonald & Alison G. Paquette

Center for Child Health, Behavior, and Development, Seattle Children’s Research Institute, Seattle, WA, USA

Brennan H. Baker & Sheela Sathyanarayana

Department of Pediatrics, University of Washington, Seattle, WA, USA

Sheela Sathyanarayana & Alison G. Paquette

Department of Epidemiology, University of Washington, Seattle, WA, USA

Sheela Sathyanarayana

Department of Biostatistics, University of Washington, Seattle, WA, USA

Adam A. Szpiro

Center for Developmental Biology and Regenerative Medicine, Seattle Children’s Research Institute, Seattle, WA, USA

Alison G. Paquette

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Contributions

BB: conceptualization, methodology, software, formal analysis, visualization, writing—original draft, writing—review and editing. SS: supervision, funding acquisition, writing—review and editing. AS: supervision, methodology, writing—review and editing. JM: supervision, methodology, software, writing—review and editing. AP: supervision, methodology, visualization, writing—review and editing.

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Correspondence to Brennan H. Baker .

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Baker, B.H., Sathyanarayana, S., Szpiro, A.A. et al. RNAseqCovarImpute: a multiple imputation procedure that outperforms complete case and single imputation differential expression analysis. Genome Biol 25 , 236 (2024). https://doi.org/10.1186/s13059-024-03376-7

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DOI : https://doi.org/10.1186/s13059-024-03376-7

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