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• 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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Frequently asked questions.

Yes, in fact a case study is a very good option in your dissertation. There are multiple ways to implement a case study in your thesis. For instance, one main study which is in depth and complex or you could feature multiple case studies.

Case studies are a way to research a particular field, group, people and situation. The topic of research is studied deeply and thoroughly in order to solve a problem or uncover information. Case studies are a type of qualitative research.

If you are ready to find a masters course check out Masters Compare.

Prof Martyn Denscombe, author of “ The Good Research Guide, 6th edition ”, gives expert advice on how to use a case study in your masters dissertation. 

There are two main examples for how to use a case study in your masters dissertation, namely quantitative and qualitative case studies.

First, a case study provides a platform that allows you to study a situation in depth and produce the level of academic inquiry that is expected in a master’s degree. In the context of any master’s programme the dissertation operates as something of a showcase for a student’s abilities.

It can easily make the difference between getting a merit and a distinction in the final award of degree. It is important, therefore, to base the work on an approach that allows things to be explored in sufficient depth and detail to warrant a good grade.

Second, case studies can be useful in a practical sense. It is possible to complete a case study in a relatively short period of intense study and so it is the kind of research that is feasible in terms of the kind of time constraints that face master’s students as they enter the final stages of their programme of study.

Added to which a case study can also be a rather convenient form of research, avoiding the time and costs of travel to multiple research sites. The use of case studies, then, would appear to be an attractive proposition. But it is not an approach that should be used naively without consideration of its limitations or potential pitfalls.

To be a good case study the research needs to consider certain key issues. If they are not addressed it will considerably lower the value of the master’s degree. For instance, a good case study needs to:

• Be crystal clear about the purpose for which the research is being conducted
• Justify the selection of the particular case being studied
• Describe how the chosen case compares with others of its type
• Explain the basis on which any generalizations can be made from the findings

This is where The Good Research Guide, 6th edition becomes so valuable. It not only identifies the key points that need to be addressed in order to conduct a competent questionnaire survey.

It gets right to the heart of the matter with plenty of practical guidance on how to deal with issues. Using plain language, this bestselling book covers a range of alternative strategies and methods for conducting small-scale social research projects. It outlines some of the main ways in which the data can be analysed.

Read Prof Martyn Denscombe’s advice on using a questionnaire survey for your postgraduate dissertation

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Can Dissertation be a Case Study: Research Example and Format

write Case study as dissertation

Also known as a thesis, a dissertation usually comes at the end of a degree course. Unlike essays and other standard research papers, a dissertation is a large project that requires a deeper depth of research.

The research can take up to the final six months of your degree course. The significance of this type of research is to test the ability of a student to do independent research. A student comes up with his or her own idea, does a thorough research then structures the content to make a final research paper.

In essence, this stage of your degree course teaches you how to manage your time and sharpen your individual working skills.

A student usually works with the department supervisor to make dissertation writing easier. The supervisor can help in planning the writing of the dissertation. The purpose of the supervisor is to provide guidance, feedback and advice as you progress from stage one of writing to the end.

People Also Read: Test Taking Strategies For Students: A Comprehensive Guide

Can Dissertation be a Case Study?

There are very few instances when a dissertation is used as a case study because of the differences.

If you opt to use your dissertation as a case study, ensure that you do not focus on providing solution to the problem.

If it is an already written dissertation, it requires a lot of editing. In a dissertation, you provide the solution to a problem, but in case studies, only analysis of events is enough to complete the project.

How to Incorporate Case Study into Your Dissertation

A good qualitative case study can form the perfect basis of your dissertation and save you a lot of time.

To start with, a case study gives you the avenue to deeply analyze a situation. Precisely so, it will be easier for you to exhibit the academic survey level that your degree requires.

A good case study can be used in your dissertation in a practical sense.

In the final stages of your degree, time constraints are tight and a case study will take you a relatively short period to complete unlike a dissertation. Therefore, it is an appropriate form of research that saves time taken to navigate multiple research sites.

However, to incorporate a case study into your dissertation, pay attention to the potential drawbacks and limitations involved.

To avoid lowering the value and quality of your research, the following are some of the considerations to observe when selecting a proper case study for your dissertation:

a) The case study ought to be clear and in uniformity with the research purpose .

b) The particular case you choose, should be justified.

c) There has to be a clear explanation concerning the basis of the overviews made from your research results.

d) The case study should have a comparison between the chosen cases and others .

To date, there are many students who use case studies as an obvious option for research projects. 

All in all, be careful how you implement the study into your research as many professors may view dissertation as one that lacks rigor and consistency. Despite this skepticism, case studies can offer more exhaustive insights that an ordinary research cannot achieve.

People Also Read: Hardest Essay Topics For High School and University Students

How to Write Case Study Only as Your Dissertation

A case study and a dissertation share a lot of similarities but they are not the same.

In case studies, there is a full introduction of a topic. But, the opinion of the writer and other similar works do not need citation. Equally, a dissertation requires the citing of a writer’s view as well as that of other similar works. 

A student who is about to graduate is supposed to know instances when case studies can be used as dissertation and when they cannot.

If you are worried about writing a great dissertation that will excite your lecturer, you can opt for the case study method.

Here are important steps to follow in writing a case study only as your dissertation:

• Start by defining the particular question you are going to address in the paper. It will be easier if you create specific questions that will answer the main parts of the situation. Develop your focus of research to get all the information about the topic.
• Design the process of the case study. Come up with a clear roadmap of the selected real life cases and ensure you know the reason why you have chosen them. Also, do not forget to enlighten more information about the research methods you intend to adopt for the purposes of data collection and analysis.
• A case study written only as a dissertation needs a huge amount of data. Needless to say, a writer should develop a clear plan for data collection.
• With your plan ready, proceed to the field and collect data. At this stage, do not make any interpretation of results until the research process is complete.
• Having done that, present the data by reporting in a flowing manner.  Use a simple language for readers to understand your interpretations effortlessly.

Formatting the Case Study        

Following the right format guarantees a good case study paper that you can use to impress the professor as a dissertation. 

Start with an introduction or an exclusive summary so as to inform the reader about the findings and analysis of the case study.

Secondly, provide background information by writing clear facts and pinpointing the topic issues to your audience.

The next part is to embark on the methods and findings.

This is a discussion that entails verdicts of the case you have chosen and should be divided into separate sections for easier understanding. 

Afterwards, come to the section where you will provide the recommendations and how to implement them. Here, a writer should discuss the solution chosen, give clear reasons why it is the right one and how to put it into practice.

Good solutions usually focus on realistic means of improving the situation or solving it.

You can give evidence as a backup for the solutions you have proposed.  The final part is to write a conclusion that summarizes all the important points from the evaluations and solutions of the case study.

3 Examples of Case Study Topics to Write as Dissertations

To arrive at a good case topic idea, hunt for the ultimate topic that inspires you. From the possible list of selection you have, narrow down to topics that reflect the main idea you want.

After arriving at the topic of choice, select the right methodology for researching. Below are good topics you can select for your case study:

1. Why start-up businesses are on a steady rise.

2. Research study case on patients with Omicron corona virus and the latest nursing methods for the virus.

3. Case study on the rise and rise of Tiktok.

People Also Read: 1200 Words Essay: How Many Pages, How to Write& It’s Structure

Regardless of the course you have selected or your academic objectives, a college student needs a good case study. The quality of this study will depend on the topic you select.

Therefore, if you select a topic correctly, your ideas will be well organized and you can use available research methodologies to write an interesting case study.

There are different categories of ideas you can base your study on depending on the subject you want. You can focus on titles ranging from information technology to psychology, education and environmental science.

There are also good topic ideas you can derive from applied physics, marketing, management, human right case studies or even nursing.

When not handling complex essays and academic writing tasks, Josh is busy advising students on how to pass assignments. In spare time, he loves playing football or walking with his dog around the park.

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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.

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What is case study research?

Last updated

8 February 2023

Reviewed by

Cathy Heath

Short on time? Get an AI generated summary of this article instead

Suppose a company receives a spike in the number of customer complaints, or medical experts discover an outbreak of illness affecting children but are not quite sure of the reason. In both cases, carrying out a case study could be the best way to get answers.

Organization

Case studies can be carried out across different disciplines, including education, medicine, sociology, and business.

Most case studies employ qualitative methods, but quantitative methods can also be used. Researchers can then describe, compare, evaluate, and identify patterns or cause-and-effect relationships between the various variables under study. They can then use this knowledge to decide what action to take. 

Another thing to note is that case studies are generally singular in their focus. This means they narrow focus to a particular area, making them highly subjective. You cannot always generalize the results of a case study and apply them to a larger population. However, they are valuable tools to illustrate a principle or develop a thesis.

Analyze case study research

Dovetail streamlines case study research to help you uncover and share actionable insights

• What are the different types of case study designs?

Researchers can choose from a variety of case study designs. The design they choose is dependent on what questions they need to answer, the context of the research environment, how much data they already have, and what resources are available.

Here are the common types of case study design:

Explanatory

An explanatory case study is an initial explanation of the how or why that is behind something. This design is commonly used when studying a real-life phenomenon or event. Once the organization understands the reasons behind a phenomenon, it can then make changes to enhance or eliminate the variables causing it. 

Here is an example: How is co-teaching implemented in elementary schools? The title for a case study of this subject could be “Case Study of the Implementation of Co-Teaching in Elementary Schools.”

Descriptive

An illustrative or descriptive case study helps researchers shed light on an unfamiliar object or subject after a period of time. The case study provides an in-depth review of the issue at hand and adds real-world examples in the area the researcher wants the audience to understand. 

The researcher makes no inferences or causal statements about the object or subject under review. This type of design is often used to understand cultural shifts.

Here is an example: How did people cope with the 2004 Indian Ocean Tsunami? This case study could be titled "A Case Study of the 2004 Indian Ocean Tsunami and its Effect on the Indonesian Population."

Exploratory

Exploratory research is also called a pilot case study. It is usually the first step within a larger research project, often relying on questionnaires and surveys . Researchers use exploratory research to help narrow down their focus, define parameters, draft a specific research question , and/or identify variables in a larger study. This research design usually covers a wider area than others, and focuses on the ‘what’ and ‘who’ of a topic.

Here is an example: How do nutrition and socialization in early childhood affect learning in children? The title of the exploratory study may be “Case Study of the Effects of Nutrition and Socialization on Learning in Early Childhood.”

An intrinsic case study is specifically designed to look at a unique and special phenomenon. At the start of the study, the researcher defines the phenomenon and the uniqueness that differentiates it from others. 

In this case, researchers do not attempt to generalize, compare, or challenge the existing assumptions. Instead, they explore the unique variables to enhance understanding. Here is an example: “Case Study of Volcanic Lightning.”

This design can also be identified as a cumulative case study. It uses information from past studies or observations of groups of people in certain settings as the foundation of the new study. Given that it takes multiple areas into account, it allows for greater generalization than a single case study. 

The researchers also get an in-depth look at a particular subject from different viewpoints.  Here is an example: “Case Study of how PTSD affected Vietnam and Gulf War Veterans Differently Due to Advances in Military Technology.”

Critical instance

A critical case study incorporates both explanatory and intrinsic study designs. It does not have predetermined purposes beyond an investigation of the said subject. It can be used for a deeper explanation of the cause-and-effect relationship. It can also be used to question a common assumption or myth. 

The findings can then be used further to generalize whether they would also apply in a different environment.  Here is an example: “What Effect Does Prolonged Use of Social Media Have on the Mind of American Youth?”

Instrumental

Instrumental research attempts to achieve goals beyond understanding the object at hand. Researchers explore a larger subject through different, separate studies and use the findings to understand its relationship to another subject. This type of design also provides insight into an issue or helps refine a theory. 

For example, you may want to determine if violent behavior in children predisposes them to crime later in life. The focus is on the relationship between children and violent behavior, and why certain children do become violent. Here is an example: “Violence Breeds Violence: Childhood Exposure and Participation in Adult Crime.”

Evaluation case study design is employed to research the effects of a program, policy, or intervention, and assess its effectiveness and impact on future decision-making. 

For example, you might want to see whether children learn times tables quicker through an educational game on their iPad versus a more teacher-led intervention. Here is an example: “An Investigation of the Impact of an iPad Multiplication Game for Primary School Children.” 

• When do you use case studies?

Case studies are ideal when you want to gain a contextual, concrete, or in-depth understanding of a particular subject. It helps you understand the characteristics, implications, and meanings of the subject.

They are also an excellent choice for those writing a thesis or dissertation, as they help keep the project focused on a particular area when resources or time may be too limited to cover a wider one. You may have to conduct several case studies to explore different aspects of the subject in question and understand the problem.

• What are the steps to follow when conducting a case study?

1. Select a case

Once you identify the problem at hand and come up with questions, identify the case you will focus on. The study can provide insights into the subject at hand, challenge existing assumptions, propose a course of action, and/or open up new areas for further research.

2. Create a theoretical framework

While you will be focusing on a specific detail, the case study design you choose should be linked to existing knowledge on the topic. This prevents it from becoming an isolated description and allows for enhancing the existing information. 

It may expand the current theory by bringing up new ideas or concepts, challenge established assumptions, or exemplify a theory by exploring how it answers the problem at hand. A theoretical framework starts with a literature review of the sources relevant to the topic in focus. This helps in identifying key concepts to guide analysis and interpretation.

3. Collect the data

Case studies are frequently supplemented with qualitative data such as observations, interviews, and a review of both primary and secondary sources such as official records, news articles, and photographs. There may also be quantitative data —this data assists in understanding the case thoroughly.

4. Analyze your case

The results of the research depend on the research design. Most case studies are structured with chapters or topic headings for easy explanation and presentation. Others may be written as narratives to allow researchers to explore various angles of the topic and analyze its meanings and implications.

In all areas, always give a detailed contextual understanding of the case and connect it to the existing theory and literature before discussing how it fits into your problem area.

• What are some case study examples?

What are the best approaches for introducing our product into the Kenyan market?

How does the change in marketing strategy aid in increasing the sales volumes of product Y?

How can teachers enhance student participation in classrooms?

How does poverty affect literacy levels in children?

Case study topics

Case study of product marketing strategies in the Kenyan market

Case study of the effects of a marketing strategy change on product Y sales volumes

Case study of X school teachers that encourage active student participation in the classroom

Case study of the effects of poverty on literacy levels in children

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Writing a Case Study

What is a case study?

A Case study is: 

• An in-depth research design that primarily uses a qualitative methodology but sometimes​​ includes quantitative methodology.
• Used to examine an identifiable problem confirmed through research.
• Used to investigate an individual, group of people, organization, or event.
• Used to mostly answer "how" and "why" questions.

What are the different types of case studies?

Note: These are the primary case studies. As you continue to research and learn

about case studies you will begin to find a robust list of different types. 

Who are your case study participants?

What is triangulation ? 

Validity and credibility are an essential part of the case study. Therefore, the researcher should include triangulation to ensure trustworthiness while accurately reflecting what the researcher seeks to investigate.

How to write a Case Study?

When developing a case study, there are different ways you could present the information, but remember to include the five parts for your case study.

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What is a Case Study and Why should I Use It in My PhD Dissertation? Understanding the purpose of case studies in research.

A case study can provide appropriate research design in a qualitative or quantitative study to to gain concrete, contextual, in-depth knowledge and multi-faceted understanding of a complex issue in its real-life context. The case study can be a great tool for providing insight and developing theories in the avenue of present research.

What is a case study?

A case study is a structured, focused, in-depth look at a particular issue or topic that reports on the findings and conclusions of researchers who have studied the case. A case study is not intended to be an exploratory analysis or to make sweeping generalizations. Rather, it is an objective, focused, and structured approach to understand the specific circumstances of an issue or the people, places, and things that make up a society. Prepared to the best of the researchers knowledge, a case study is a unique research method. In fact, case studies are the most common type of qualitative research. A case study is often a combination of interviews, focus groups, documentation, and research documentation.

Why do researchers use case study?

Case studies often contain detailed, in-depth examination of a particular issue or topic that reports on the findings and conclusions of researchers who have studied the case. Case studies are excellent for gaining insight and understanding in the following ways: – 

• Focus on one aspect of the phenomena being studied
• Give the researcher a window into the participants’ world 
• Explain the decision making process involved in data collection, analysis, and presentation 
• Allow for in-depth examination of the methodology

How to do a case study in PhD research

To conduct a case study, the students must first adhere to the university requirements and establish a strong subject knowledge in the domain of study. This is to help the researcher design the case study in a controlled environment. The case study must:

Be descriptive – Be specific – Be analytical – Be critical – Be narrative – Be written within required format

Key elements of a successful case study

The basic elements of a successful case study include: – 

• The phenomenon 
• The context 
• The methodology 
• The conclusions 
• The recommendations 
• The detail of resources used  

Research design using cases

Research designs that incorporate the use of case studies are often qualitative or quantitative in nature. A quantitative approach to the study of a phenomenon could involve questionnaires to collect data about the respondents’ experiences. On the other hand, a qualitative approach could involve in-depth interviews to understand the thoughts, feelings, and experiences of people who are experiencing the same phenomenon as the research team. Case studies can also be used in the analysis of the validity of a plan. For example, a case study examining the feasibility of a new project could examine the cost, risks, and benefits of undertaking the study and the study’s design.

The case study can be used in various design settings:

• Explanatory case studies aim to answer ‘how’ or ’why’ questions and involve an accurate description of the event or situation under study rather than the researcher’s thoughts.
• A descriptive case study is one that is focused and detailed to illustrate an unfamiliar subject that the researcher wants the audience to understand and the phenomenon under study is carefully scrutinized.
• Exploratory case studies aim to find answers to the questions of ‘what’ or ‘who’. This is often conducted on the premise of a larger research problem to narrow the focus of the study and reach a specific research objective.

Should I be using case studies in my research?

Eisenhardt (1989) says that case studies are:

“Particularly well suited to new research areas or research areas for

which existing theory seems inadequate. This type of work is highly

complementary to incremental theory building from normal science

research. The former is useful in early stages of research on a topic or

when a fresh perspective is needed, whilst the latter is useful in later

stages of knowledge” (pp.548-549).

There is a certain skepticism about the usefulness of case studies as an objective research method considering its many limitations like the reliability of the respondents and the behavioral differences that can contribute to the inadequacy of the information provided by the subjects of the case, the issue of possibility of generalization of the findings of a case study considering the narrow and focussed approach that case studied utilize and finally the researcher bias which forms the main disadvantage to an objective study. The researcher should also consider the efficiency of using case studies in his or her research because of the detailed nature of this method that is not only dependent on factors beyond control but also intensive in preparation and deduction of conclusions.

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• Case Study | Definition, Examples & Methods

Case Study | Definition, Examples & Methods

Published on 5 May 2022 by Shona McCombes . Revised on 30 January 2023.

A case study is a detailed study of a specific subject, such as a person, group, place, event, organisation, 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 analyse the case.

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

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.

If you find yourself aiming to simultaneously investigate and solve an issue, consider conducting action research . As its name suggests, action research conducts research and takes action at the same time, and is highly iterative and flexible. 

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

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 .

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

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 analyse 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.

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Library Guides

Dissertations 4: methodology: methods.

• Introduction & Philosophy
• Methodology

Primary & Secondary Sources, Primary & Secondary Data

When describing your research methods, you can start by stating what kind of secondary and, if applicable, primary sources you used in your research. Explain why you chose such sources, how well they served your research, and identify possible issues encountered using these sources.  

Definitions  

There is some confusion on the use of the terms primary and secondary sources, and primary and secondary data. The confusion is also due to disciplinary differences (Lombard 2010). Whilst you are advised to consult the research methods literature in your field, we can generalise as follows:  

Secondary sources 

Secondary sources normally include the literature (books and articles) with the experts' findings, analysis and discussions on a certain topic (Cottrell, 2014, p123). Secondary sources often interpret primary sources.  

Primary sources 

Primary sources are "first-hand" information such as raw data, statistics, interviews, surveys, law statutes and law cases. Even literary texts, pictures and films can be primary sources if they are the object of research (rather than, for example, documentaries reporting on something else, in which case they would be secondary sources). The distinction between primary and secondary sources sometimes lies on the use you make of them (Cottrell, 2014, p123). 

Primary data 

Primary data are data (primary sources) you directly obtained through your empirical work (Saunders, Lewis and Thornhill 2015, p316). 

Secondary data 

Secondary data are data (primary sources) that were originally collected by someone else (Saunders, Lewis and Thornhill 2015, p316).   

Comparison between primary and secondary data   

Use  

Virtually all research will use secondary sources, at least as background information. 

Often, especially at the postgraduate level, it will also use primary sources - secondary and/or primary data. The engagement with primary sources is generally appreciated, as less reliant on others' interpretations, and closer to 'facts'. 

The use of primary data, as opposed to secondary data, demonstrates the researcher's effort to do empirical work and find evidence to answer her specific research question and fulfill her specific research objectives. Thus, primary data contribute to the originality of the research.    

Ultimately, you should state in this section of the methodology: 

What sources and data you are using and why (how are they going to help you answer the research question and/or test the hypothesis. 

If using primary data, why you employed certain strategies to collect them. 

What the advantages and disadvantages of your strategies to collect the data (also refer to the research in you field and research methods literature). 

Quantitative, Qualitative & Mixed Methods

The methodology chapter should reference your use of quantitative research, qualitative research and/or mixed methods. The following is a description of each along with their advantages and disadvantages. 

Quantitative research 

Quantitative research uses numerical data (quantities) deriving, for example, from experiments, closed questions in surveys, questionnaires, structured interviews or published data sets (Cottrell, 2014, p93). It normally processes and analyses this data using quantitative analysis techniques like tables, graphs and statistics to explore, present and examine relationships and trends within the data (Saunders, Lewis and Thornhill, 2015, p496). 

Qualitative research  

Qualitative research is generally undertaken to study human behaviour and psyche. It uses methods like in-depth case studies, open-ended survey questions, unstructured interviews, focus groups, or unstructured observations (Cottrell, 2014, p93). The nature of the data is subjective, and also the analysis of the researcher involves a degree of subjective interpretation. Subjectivity can be controlled for in the research design, or has to be acknowledged as a feature of the research. Subject-specific books on (qualitative) research methods offer guidance on such research designs.  

Mixed methods 

Mixed-method approaches combine both qualitative and quantitative methods, and therefore combine the strengths of both types of research. Mixed methods have gained popularity in recent years.  

When undertaking mixed-methods research you can collect the qualitative and quantitative data either concurrently or sequentially. If sequentially, you can for example, start with a few semi-structured interviews, providing qualitative insights, and then design a questionnaire to obtain quantitative evidence that your qualitative findings can also apply to a wider population (Specht, 2019, p138). 

Ultimately, your methodology chapter should state: 

Whether you used quantitative research, qualitative research or mixed methods. 

Why you chose such methods (and refer to research method sources). 

Why you rejected other methods. 

How well the method served your research. 

The problems or limitations you encountered. 

Doug Specht, Senior Lecturer at the Westminster School of Media and Communication, explains mixed methods research in the following video:

LinkedIn Learning Video on Academic Research Foundations: Quantitative

The video covers the characteristics of quantitative research, and explains how to approach different parts of the research process, such as creating a solid research question and developing a literature review. He goes over the elements of a study, explains how to collect and analyze data, and shows how to present your data in written and numeric form.

Link to quantitative research video

Some Types of Methods

There are several methods you can use to get primary data. To reiterate, the choice of the methods should depend on your research question/hypothesis. 

Whatever methods you will use, you will need to consider: 

why did you choose one technique over another? What were the advantages and disadvantages of the technique you chose? 

what was the size of your sample? Who made up your sample? How did you select your sample population? Why did you choose that particular sampling strategy?) 

ethical considerations (see also tab...)  

safety considerations  

validity  

feasibility  

recording  

procedure of the research (see box procedural method...).  

Check Stella Cottrell's book  Dissertations and Project Reports: A Step by Step Guide  for some succinct yet comprehensive information on most methods (the following account draws mostly on her work). Check a research methods book in your discipline for more specific guidance.  

Experiments 

Experiments are useful to investigate cause and effect, when the variables can be tightly controlled. They can test a theory or hypothesis in controlled conditions. Experiments do not prove or disprove an hypothesis, instead they support or not support an hypothesis. When using the empirical and inductive method it is not possible to achieve conclusive results. The results may only be valid until falsified by other experiments and observations. 

For more information on Scientific Method, click here . 

Observations 

Observational methods are useful for in-depth analyses of behaviours in people, animals, organisations, events or phenomena. They can test a theory or products in real life or simulated settings. They generally a qualitative research method.  

Questionnaires and surveys 

Questionnaires and surveys are useful to gain opinions, attitudes, preferences, understandings on certain matters. They can provide quantitative data that can be collated systematically; qualitative data, if they include opportunities for open-ended responses; or both qualitative and quantitative elements. 

Interviews  

Interviews are useful to gain rich, qualitative information about individuals' experiences, attitudes or perspectives. With interviews you can follow up immediately on responses for clarification or further details. There are three main types of interviews: structured (following a strict pattern of questions, which expect short answers), semi-structured (following a list of questions, with the opportunity to follow up the answers with improvised questions), and unstructured (following a short list of broad questions, where the respondent can lead more the conversation) (Specht, 2019, p142). 

This short video on qualitative interviews discusses best practices and covers qualitative interview design, preparation and data collection methods. 

Focus groups   

In this case, a group of people (normally, 4-12) is gathered for an interview where the interviewer asks questions to such group of participants. Group interactions and discussions can be highly productive, but the researcher has to beware of the group effect, whereby certain participants and views dominate the interview (Saunders, Lewis and Thornhill 2015, p419). The researcher can try to minimise this by encouraging involvement of all participants and promoting a multiplicity of views. 

This video focuses on strategies for conducting research using focus groups.  

Check out the guidance on online focus groups by Aliaksandr Herasimenka, which is attached at the bottom of this text box. 

Case study 

Case studies are often a convenient way to narrow the focus of your research by studying how a theory or literature fares with regard to a specific person, group, organisation, event or other type of entity or phenomenon you identify. Case studies can be researched using other methods, including those described in this section. Case studies give in-depth insights on the particular reality that has been examined, but may not be representative of what happens in general, they may not be generalisable, and may not be relevant to other contexts. These limitations have to be acknowledged by the researcher.     

Content analysis 

Content analysis consists in the study of words or images within a text. In its broad definition, texts include books, articles, essays, historical documents, speeches, conversations, advertising, interviews, social media posts, films, theatre, paintings or other visuals. Content analysis can be quantitative (e.g. word frequency) or qualitative (e.g. analysing intention and implications of the communication). It can detect propaganda, identify intentions of writers, and can see differences in types of communication (Specht, 2019, p146). Check this page on collecting, cleaning and visualising Twitter data.

Extra links and resources:  

Research Methods  

A clear and comprehensive overview of research methods by Emerald Publishing. It includes: crowdsourcing as a research tool; mixed methods research; case study; discourse analysis; ground theory; repertory grid; ethnographic method and participant observation; interviews; focus group; action research; analysis of qualitative data; survey design; questionnaires; statistics; experiments; empirical research; literature review; secondary data and archival materials; data collection. 

Doing your dissertation during the COVID-19 pandemic  

Resources providing guidance on doing dissertation research during the pandemic: Online research methods; Secondary data sources; Webinars, conferences and podcasts; 

• Virtual Focus Groups Guidance on managing virtual focus groups

5 Minute Methods Videos

The following are a series of useful videos that introduce research methods in five minutes. These resources have been produced by lecturers and students with the University of Westminster's School of Media and Communication. 

Case Study Research

Research Ethics

Quantitative Content Analysis 

Sequential Analysis 

Qualitative Content Analysis 

Thematic Analysis 

Social Media Research 

Mixed Method Research 

Procedural Method

In this part, provide an accurate, detailed account of the methods and procedures that were used in the study or the experiment (if applicable!). 

Include specifics about participants, sample, materials, design and methods. 

If the research involves human subjects, then include a detailed description of who and how many participated along with how the participants were selected.  

Describe all materials used for the study, including equipment, written materials and testing instruments. 

Identify the study's design and any variables or controls employed. 

Write out the steps in the order that they were completed. 

Indicate what participants were asked to do, how measurements were taken and any calculations made to raw data collected. 

Specify statistical techniques applied to the data to reach your conclusions. 

Provide evidence that you incorporated rigor into your research. This is the quality of being thorough and accurate and considers the logic behind your research design. 

Highlight any drawbacks that may have limited your ability to conduct your research thoroughly. 

You have to provide details to allow others to replicate the experiment and/or verify the data, to test the validity of the research. 

Bibliography

Cottrell, S. (2014). Dissertations and project reports: a step by step guide. Hampshire, England: Palgrave Macmillan.

Lombard, E. (2010). Primary and secondary sources.  The Journal of Academic Librarianship , 36(3), 250-253

Saunders, M.N.K., Lewis, P. and Thornhill, A. (2015).  Research Methods for Business Students.  New York: Pearson Education. 

Specht, D. (2019).  The Media And Communications Study Skills Student Guide . London: University of Westminster Press.  

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• Next: Ethics >>
• Last Updated: Sep 14, 2022 12:58 PM
• URL: https://libguides.westminster.ac.uk/methodology-for-dissertations

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When and How to Use a Case Study for Research

May 17, 2021 (Updated: May 4, 2023)

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What Is Case Study Research?

Types of case studies, when should you use a case study, case study benefits, case study limitations, how to write a case study.

Imagine your company receives a string of negative reviews online. You notice a few common themes among the complaints, but you still aren’t quite sure what went wrong. Or suppose an old blog post suddenly went viral, and you’d like to know why and how to do it again. In both of these situations, a case study could be the best way to find answers.

A case study is a process whereby researchers examine a specific subject in a thorough, detailed way. The subject of a case study could be an individual, a group, a community, a business, an organization, an event, or a phenomenon. Regardless of the type of subject, case studies are in-depth investigations designed to identify patterns and cause-and-effect relationships. Case studies are often used by researchers in the field of psychology , medicine, business, social work, anthropology, education, or political science.

Because they are singular in their focus and often rely on qualitative data, case studies tend to be highly subjective. The results of a single case study cannot always be generalized and applied to the larger population. However, case studies can be valuable tools for developing a thesis or illustrating a principle. They can help researchers understand, describe, compare, and evaluate different aspects of an issue or question.

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Case studies can be classified according to their purpose or their subject. For instance, a case study can focus on any of the following:

• A person:  Some case studies focus on one particular person. Often, the subject will be an individual with some rare characteristic or experience.
• A group:  Group case studies could look at a family, a group of coworkers, or a friend group. It could be people thrown together by circumstance or who share some bond or relationship. A group case study could even focus on an entire community of people.
• An organization:  An organizational case study could focus on a business, a nonprofit, an institution, or any other formal entity. The study could look at the people in the organization, the processes they use, or an incident at the organization.
• A location:  An event case study focuses on a specific area. It could be used to study environmental and population changes or to examine how people use the location.
• An event:  Event case studies can be used to cover anything from a natural disaster to a political scandal. Often, these case studies are conducted retrospectively, as an investigation into a past event.

In addition to different types of subjects, case studies often have different designs or purposes. Here are a few of the most common types of case studies:

• Explanatory:  An explanatory case study tries to explain the why or how behind something. This type of case study works well when studying an event or phenomenon, like an airplane crash or unexpected power outage.
• Descriptive:  A descriptive, or illustrative, case study is designed to shed light on an unfamiliar subject. Case studies like this provide in-depth, real-world examples of whatever the researcher wants to help the audience understand. For instance, a descriptive case study could focus on the experience of a mother with postpartum depression or on a young adult who has aged out of the foster care system.
• Exploratory:  An exploratory case study, or pilot case study, often serves as the first step in a larger research project. Researchers may use a case study to help them narrow their focus, draft a specific research question, and guide the parameters of a formal, large-scale study.
• Intrinsic:  An intrinsic case study has no goal beyond a deeper understanding of its subject. In this type of study, researchers are not trying to make generalized conclusions, challenge existing assumptions, or make any compare-and-contrast connections. The most interesting thing about the study is the subject itself.
• Critical Instance:  A critical instance case study is similar to an explanatory or intrinsic study. Like an intrinsic study, it may have no predetermined purpose beyond investigating the subject. Like an explanatory study, it may be used to explain a cause-and-effect relationship. A critical instance case study may also be used to call into question a commonly held assumption or popular theory.
• Instrumental:  An instrumental case study is the opposite of an intrinsic study because it serves a purpose beyond understanding the immediate subject. In this type of study, researchers explore a larger question through an individual case or cases. For instance, researchers could use a handful of case studies to investigate the relationship between social media use and happiness.
• Cumulative:  A cumulative, or collective, case study uses information from several past studies as the basis for a new study. Because it takes into account multiple case studies, a cumulative study allows for greater generalization than a single case study. It can also be a more time- and cost-effective option since it makes use of existing research.

Case studies are often used in the exploratory phase of research to gather qualitative data. They can also be used to create, support, or refute a hypothesis and guide future research. For instance, a marketing professional might conduct a case study to discover why a viral ad campaign was so successful . They can then take any lessons they glean from the case study and apply them to future marketing efforts. A psychologist could use a case study to form a theory about the best way to treat a specific disorder. That theory could then be tested later through a large-scale controlled study.

Case studies are a good way to explore a real-world topic in-depth, illustrate a point, discuss the implications or meaning of an event, or compare the experiences of different individuals. A trainer may use a case study to bring to life what would otherwise be an abstract series of recommended action steps or to spark a conversation about how to respond in a specific scenario. Similarly, professors can use case studies to highlight key concepts from a lecture and pose questions to test students’ understanding of the material.

In some situations, case studies are the only way to compile quantitative data in an ethical manner. For instance, many of the recommendations that doctors make regarding what is or is not safe during pregnancy are based on case studies. It wouldn’t be ethical to conduct a controlled study that exposes pregnant women to potentially harmful substances, so doctors rely on the anecdotal evidence provided by case studies to find correlations and draw their conclusions.

Case studies can also be used to gather data that would be otherwise impossible or impractical to obtain. Students often use case studies for their thesis or dissertation when they lack the time or resources to conduct large-scale research. Zoologists might use existing case studies to determine the success rate of reintroducing rehabilitated animals into the wild. A historian could use case studies to explore the strategies used by dictators to gain and maintain power.

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Case studies can be used on their own or as a complement to other research methods, depending on the situation. The examples above are just a few instances where case studies can be useful. Case studies also work well for the following:

Providing Insight Through Qualitative Data

Case studies generally provide more qualitative data as opposed to quantitative data , and that makes them an invaluable tool for gathering insight into complex topics. Psychologists, for instance, use case studies to better understand human behavior. Crafting theories on the motives behind human actions would be difficult with quantitative data alone. The information gleaned through case studies may be subjective, but so is much of what makes us human. As individuals, we each have a unique blend of emotions, attitudes, opinions, motivations, and behaviors. Objective quantitative data is rarely the best way to identify and explain these nuances.

By their very nature, case studies allow more more intensive, in-depth study than other research methods. Rather than aiming for a large sample size, case studies follow a single subject. Often case studies are conducted over a longer period of time, and the narrow focus allows researchers to gather more detail than would be possible in a study of thousands of people. The information gleaned may not be representative of the broader population, but it does provide richer insight into the subject than other research methods.

Identifying Avenues for Future Research

Case studies are often used as the first step in a larger research project. The results of a case study cannot necessarily be generalized, but they can help researchers narrow their focus. For instance, researchers in the medical field might conduct a case study on a patient who survived an injury that typically proves fatal.

Over the course of the study, researchers may identify two or three ways in which this patient’s situation differed from others they have seen. Perhaps they identify something unique in the patient’s DNA or lifestyle choices or in the steps doctors took to treat the injury. Letting that information guide them, researchers could use other methods to deepen their understanding of those factors and perhaps develop new treatments or preventative recommendations.

Case studies can also be used in the fields of social work, politics, and anthropology to draw attention to a widespread problem and spur more research. A detailed narrative about one person’s experience will inspire more compassion than an academic paper filled with quantitative data. Stories often have a greater impact than statistics.

Challenging, Testing, or Developing Theories

Case studies can be particularly useful in the process of forming and testing theories. A case study may lead researchers to form a new theory or call into a question an existing one. They are an invaluable tool for identifying exceptions to a rule or disproving conventional wisdom.

For instance, a medical professional may write a case study about a patient who exhibited atypical symptoms to assert that the list of symptoms for a condition should be expanded. A psychologist could use a case study to determine whether the new treatment they devised for depression is effective, or to demonstrate that existing treatment methods are flawed. As the result of a case study, a marketing professional could suggest that consumers values have changed and that marketing best practices should be updated accordingly.

Enabling the Study of Unique Subjects

Some subjects would be impossible, impractical, or unethical to study through other research methods. This is true in the case of extremely rare phenomenon, many aspects of human behavior, and even some medical conditions.

Suppose a medical professional would like to gather more information about multiple-birth pregnancies with four or more fetuses. More information would be helpful because we have less information about them, but the reason we have less information is because they are so rare. Conducting case studies of a few women who are currently pregnant with multiples or have given birth to multiples in the past may be the only practical way to research them.

Case studies can also be used to gain insight into historical events and natural phenomenon — things we are not able to repeat at will. Case studies have also been used to study subjects such as a feral child , child prodigies, rare psychological conditions, crisis response, and more.

Helping People Better Understand Nuanced Concepts

Educators incorporate case studies into their lectures for a reason. Walking students through a detailed case study can make the abstract seem more real and draw out the nuances of a concept. Case studies can facilitate engaging discussions, spark thoughtful questions, and give students a chance to apply what they have learned to real-world situations.

Outside the classroom, case studies can be used to illustrate complex ideas. For instance, a well-constructed case study can highlight the unintended consequences of a new piece of legislation or demonstrate that depression does not always manifest in an obvious way. Case studies can help readers and listeners understand and care about an issue that does not directly affect them.

Despite their benefits, case studies do come with a few limitations. Compared to other research methods, case studies are often at a disadvantage in terms of the following:

Replicability

In most cases, scientists strive to create experiments that can be repeated by others. That way, other scientists can perform their own research and compare their results to those of the initial study. Assuming these other scientists achieve similar results, the replicability of the experiment lends credibility to the findings and theories of the original researchers.

One limitation of case studies is that they are often difficult, if not impossible, to replicate. Although this fact does not diminish the value of case studies, it does demonstrate that case studies are not a good fit for every research problem — at least, not on their own. Additional research would have to be performed to corroborate the results and prove or disprove any generalized theories generated by a case study.

Generalization

Generalization is another area in which case studies cannot match other research methods. A case study can help us challenge existing theories and form new ones, but its results cannot necessarily be generalized. The data we gather from a case study is only valid for that specific subject, and we cannot assume that our conclusions apply to the broader population.

Researchers or readers can attempt to apply the principles from a particular case to similar situations or incorporate the results into a more comprehensive theory. However, a case study by itself can only prove the existence of certain possibilities and exceptions, not a general rule.

Reliability

The reliability of case studies may be called into question for two reasons. The first objection centers on the fallibility of human memory and the question of whether subjects are being honest. Many case studies rely on subjects to self-report biographical details, their state of mind, their thoughts and feelings, or their behaviors.

The second issue is the Hawthorne effect, which refers to the tendency of individuals to modify their behavior when they know they are being observed. This effect makes it nearly impossible for researchers to ensure that the observations and conclusions of their case study are reliable.

Researcher Bias

Researcher bias is another potential issue with case studies. The results of a case study are by nature subjective and qualitative rather than objective and qualitative, and any findings rely heavily on the observations and narrative provided by the researcher. Even the best researchers are still human, and no matter how hard they try to remain objective, they will not be able to keep their findings completely free of bias.

Researchers may have biases they are not even aware of. A researcher may over-identify with the subject and lose the benefit of a dispassionate outside perspective. If the researcher already has an opinion on the subject, they may subconsciously overlook or discount facts that contradict their pre-existing assumptions. Researcher bias can affect what the researcher observes and records, as well as how they interpret and apply their observations.

Case studies can be time-consuming and expensive to conduct. Crafting a thorough case study can be a lengthy project due to the intensive, detailed nature of this type of research. Plus, once the information has been gathered, it must be interpreted. Between the observation and analysis, a case study could take months or even years to complete. Researchers will need to be heavily involved in every step of the process, putting in a lot of time, energy, focus, and effort to ensure that the case study is as informative as possible.

Now that you understand the benefits, limitations, and types of case studies, you can follow these steps to write your own:

• Determine your objective.  Write out your research problem, question, or goal. If you aren’t sure, ask yourself questions like, “What am I trying to accomplish? What do I need to know? What will success look like?” Be clear and specific. Your answers will help you choose the right type of case study for your needs.
• Review the research.  Before delving into your case study, take some time to review the research that is already available. The information you gather during this preliminary research can help guide your efforts.
• Choose a subject.  Decide what or who the subject of your case study will be. For instance, if you are conducting a case study to find out how businesses have been affected by new CDC guidelines, you will need to choose a specific restaurant or retailer. In some cases, you may need to draft a release form for the subject to sign so that you will be able to publish your study.
• Gather information.  Case studies about a person, organization, or group may rely on questionnaires or interviews to gather information. If you are studying an event, you might use a combination of academic research and witness interviews. In some cases, you will record your own observations as part of the study.
• Write a report.  Most case studies culminate in a written report, similar to a research paper. Most case studies include five sections : an introduction, a literature review, an explanation of your methods, a discussion of your findings and the implications, followed by a conclusion.
• Publish your findings.  Once you’ve written your case study, consider the most engaging way to present your findings. A well-written research article is a good place to start, but going a step further will maximize the impact of your research. For instance, you could design an infographic to highlight key findings or commission an animated video to turn your case study into a visual narrative.

Whether research is your primary occupation or only an incidental part of your job, you can benefit from a solid understanding of what case studies are, how they work, and when to use them. Use the information and steps above to design and write a case study that will provide the answers you’re looking for.

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Estimating ancestral states of complex characters: a case study on the evolution of feathers

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Feathers are a key novelty underpinning the evolutionary success of birds, yet the origin of feathers remains poorly understood. Debates about feather evolution hinge upon whether filamentous integument has evolved once or multiple time independently on the lineage leading to modern birds. These contradictory results stem from subjective methodological differences in statistical ancestral state estimates. Here we conduct a comprehensive comparison of ancestral state estimation methodologies applied to stem-group birds, testing the role of outgroup inclusion, tree time scaling method, model choice and character coding strategy. Models are compared based on their Akaike Information Criteria (AIC), mutual information, as well as the uncertainty of marginal ancestral state estimates. Our results demonstrate that ancestral state estimates of stem-bird integument are strongly influenced by tree time scaling method, outgroup selection and model choice, while character coding strategy seems to have less effect on the ancestral estimates produced. We identify the best fitting models using AIC scores and a leave-one-out cross-validation approach (LOOCV). Our analyses broadly support the independent origin of filamentous integument in dinosaurs and pterosaurs and support a younger evolutionary origin of feathers than has been suggested previously. More generally, our study highlights that special care must be taken in selecting the outgroup, tree and model when conducting ASE analyses. With respect to model selection, our results suggest that considering a LOOCV approach, may yield more reliable results than simply comparing AIC scores when the analyses involve a limited number of taxa.

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Robust pi-pd controller design: industrial simulation case studies and a real-time application.

1. Introduction

• Relative to the centroid point approaches reported in Refs. [ 3 , 4 , 16 , 18 , 22 ], the proposed method incorporates a robust design approach based on predefined gain and phase margin boundaries, which gives the designer more flexibility to obtain the desired control performances.
• Relative to the centroid point approaches reported in Refs. [ 12 , 14 , 19 , 20 ], the proposed methods are analytical and not graphical, which saves time and is easy to implement on the industrial level.
• Compared to the centroid point derived based on a robust design technique for DC–DC converter control published in Ref. [ 24 ], the suggested approach is analytical and does not call for any graphical adjustments. Furthermore, any system that can be represented as a stable SOPTD can use the suggested approach.

2. PI-PD Controller Structure

3. proposed approach, 4. simulation and real-time case studies.

• As seen in Figure 13 and Figure 14 , the suggested scenario, A = 1 ϕ = 0 ∘ , provides somewhat similar responses and results to the PI-PD-SP controller [ 2 ], even though it does have an additional mechanism to tackle long time delays.
• In contrast to PI-PD-SP [ 2 ], which completely loses stability under 70% variations in the time delay as clear in Figure 15 , the suggested scenarios A = 1 ϕ = 0 ∘ and A = 1.3 ϕ = 0 ∘ can keep the system stable with a satisfactory performance. Also, the robustness of the proposed method can be numerically seen from the real values of the gain and phase margin provided in Table 3 .
• As can be observed from the TV values listed in Table 3 , the suggested scenarios provide smoother control signals. Furthermore, as shown in Figure 13 b and Figure 14 b, the suggested method uses less control power for the transient response than the PI-PD-SP [ 2 ].

5. Conclusions

Author contributions, data availability statement, acknowledgments, conflicts of interest, list of symbols.

• Alyoussef, F.; Kaya, I. Improved adaptive dynamic non-singular terminal sliding mode controller with fractional disturbance observer. Inf. Sci. 2023 , 641 , 119110. [ Google Scholar ] [ CrossRef ]
• Singha, P.; Das, D.; Chakraborty, S.; Lloyds Raja, G. Experimentally validated predictive PI-PD control strategy for delay-dominant chemical processes. Chem. Eng. Sci. 2024 , 295 , 120197. [ Google Scholar ] [ CrossRef ]
• Alyoussef, F.; Kaya, I. Novel Tuning Rules for Adjusting the Parameters of the PI-PD Controller for Controlling Unstable Processes. Adv. Transdiscipl. Eng. 2024 , 46 , 254–261. [ Google Scholar ]
• Alyoussef, F.; Kaya, I. Simple PI-PD tuning rules based on the centroid of the stability region for controlling unstable and integrating processes. ISA Trans. 2023 , 134 , 238–255. [ Google Scholar ] [ CrossRef ] [ PubMed ]
• Kaya, I. I-PD Controller Design for Integrating Time Delay Processes Based on Optimum Analytical Formulas. IFAC-PapersOnLine 2018 , 51 , 575–580. [ Google Scholar ] [ CrossRef ]
• Zou, H.; Li, H. Improved PI-PD control design using predictive functional optimization for temperature model of a fluidized catalytic cracking unit. ISA Trans. 2017 , 67 , 215–221. [ Google Scholar ] [ CrossRef ]
• Lloyds Raja, G.; Ali, A. New PI-PD Controller Design Strategy for Industrial Unstable and Integrating Processes with Dead Time and Inverse Response. J. Control Autom. Electr. Syst. 2021 , 32 , 266–280. [ Google Scholar ] [ CrossRef ]
• Mahapatro, S.R.; Subudhi, B. A New H∞ Weighted Sensitive Function-Based Robust Multi-Loop PID Controller for a Multi-Variable System. IEEE Trans. Circuits Syst. II Express Briefs 2024 , 71 , 1256–1260. [ Google Scholar ] [ CrossRef ]
• Jain, C.; Vaishnav, N.; Jain, A.K. MTPA Control of Double Inverter Fed Wound Rotor Induction Motor Drive. IEEE Trans. Energy Convers. 2023 , 38 , 2326–2343. [ Google Scholar ] [ CrossRef ]
• Vaishnav, N.; Jain, A. Stabilizing Sets of Current PI Controllers for IM Drives with and without LC Filter. IEEE Trans. Energy Convers. 2022 , 37 , 958–969. [ Google Scholar ] [ CrossRef ]
• Mehta, U.; Aryan, P.; Raja, G.L. Tri-Parametric Fractional-Order Controller Design for Integrating Systems with Time Delay. IEEE Trans. Circuits Syst. II Express Briefs 2023 , 70 , 4166–4170. [ Google Scholar ] [ CrossRef ]
• Onat, C. A new design method for PI–PD control of unstable processes with dead time. ISA Trans. 2019 , 84 , 69–81. [ Google Scholar ] [ CrossRef ] [ PubMed ]
• Ozyetkin, M.M.; Onat, C.; Tan, N. PI-PD controller design for time delay systems via the weighted geometrical center method. Asian J. Control 2020 , 22 , 1811–1826. [ Google Scholar ] [ CrossRef ]
• İrgan, H.; Menak, R.; Tan, N. A comparative study on PI-PD controller design using stability region centroid methods for unstable, integrating and resonant systems with time delay. Meas. Control 2024 . [ Google Scholar ] [ CrossRef ]
• Imran Kalim, M.; Ali, A. New tuning strategy for series cascade control structure. IFAC-PapersOnLine 2020 , 53 , 195–200. [ Google Scholar ] [ CrossRef ]
• Alyoussef, F.; Kaya, I. Tuning proportional-integral controllers based on new analytical methods for finding centroid of stability locus for stable/unstable first-order plus dead-time processes. Proc. Inst. Mech. Eng. Part I J. Syst. Control Eng. 2022 , 236 , 818–831. [ Google Scholar ] [ CrossRef ]
• Ozyetkin, M.M. An approximation method and PID controller tuning for systems having integer order and non-integer order delay. Alex. Eng. J. 2022 , 61 , 11365–11375. [ Google Scholar ] [ CrossRef ]
• Alyoussef, F.; Kaya, I. Proportional–integral and proportional–derivative controller design based on analytically computed centroid point for controlling integrating processes. Proc. Inst. Mech. Eng. Part I J. Syst. Control Eng. 2023 , 237 , 1045–1065. [ Google Scholar ] [ CrossRef ]
• Yildirim, B.; Gheisarnejad, M.; Khooban, M.H. A Robust Non-Integer Controller Design for Load Frequency Control in Modern Marine Power Grids. IEEE Trans. Emerg. Top. Comput. Intell. 2021 , 6 , 852–866. [ Google Scholar ] [ CrossRef ]
• Yildirim, B.; Gheisarnejad, M.; Khooban, M.H. A New Parameter Tuning Technique for Noninteger Controllers in Low-Inertia Modern Power Grids. IEEE J. Emerg. Sel. Top. Ind. Electron. 2021 , 3 , 279–288. [ Google Scholar ] [ CrossRef ]
• Kalim, M.I.; Ali, A. A graphical approach for controller design with desired stability margins for a DC–DC boost converter. IET Power Electron. 2021 , 14 , 1323–1335. [ Google Scholar ] [ CrossRef ]
• Çökmez, E.; Kaya, İ. An analytical solution of fractional order PI controller design for stable/unstable/integrating processes with time delay. Turk. J. Electr. Eng. Comput. Sci. 2023 , 31 , 626–645. [ Google Scholar ] [ CrossRef ]
• Tan, N. Computation of stabilizing PI-PD controllers. Int. J. Control Autom. Syst. 2009 , 7 , 175–184. [ Google Scholar ] [ CrossRef ]
• Kumar, S.R.; Anwar, M.N.; Verma, P.; Ram, M.K.; Somanshu, S.R. H∞ Criterion Based PI Controller Design for DC-DC Step-Up Converters. IEEE J. Emerg. Sel. Top. Ind. Electron. 2023 , 5 , 402–413. [ Google Scholar ] [ CrossRef ]
• Ramana, K.V.; Majhi, S.; Gogoi, A.K. Modeling and Estimation of DC-DC Buck Converter Dynamics Using Relay Feedback Output with Performance Evaluation. IEEE Trans. Circuits Syst. II Express Briefs 2019 , 66 , 427–431. [ Google Scholar ]
• Lino, P.; Maione, G.; Stasi, S.; Padula, F.; Visioli, A. Synthesis of fractional-order PI controllers and fractional-order filters for industrial electrical drives. IEEE/CAA J. Autom. Sin. 2017 , 4 , 58–69. [ Google Scholar ] [ CrossRef ]
• Alyoussef, F.; Kaya, I. TRMS Experimental Results of New Nonlinear PID Tuned by de Algorithm. In Proceedings of the 2019 3rd International Conference on Applied Automation and Industrial Diagnostics, ICAAID 2019, Elazig, Turkey, 25–27 September 2019. [ Google Scholar ]

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Alyoussef, F.; Kaya, I.; Akrad, A. Robust PI-PD Controller Design: Industrial Simulation Case Studies and a Real-Time Application. Electronics 2024 , 13 , 3362. https://doi.org/10.3390/electronics13173362

Alyoussef F, Kaya I, Akrad A. Robust PI-PD Controller Design: Industrial Simulation Case Studies and a Real-Time Application. Electronics . 2024; 13(17):3362. https://doi.org/10.3390/electronics13173362

Alyoussef, Fadi, Ibrahim Kaya, and Ahmad Akrad. 2024. "Robust PI-PD Controller Design: Industrial Simulation Case Studies and a Real-Time Application" Electronics 13, no. 17: 3362. https://doi.org/10.3390/electronics13173362

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