Case study facts for kids

A case study is like taking a really close look at one specific thing or a few things, right in their natural setting. Imagine you want to understand how something works in real life. A case study lets you do that in great detail.

For example, in medicine, a case study might focus on one patient's illness to learn more about it. In business, it could be about how a certain company plans its actions. In politics, it might look at a specific political campaign or how a big problem affecting many people is being handled.

A case study can focus on almost anything: a person, a group, an organization, an event, a belief, or an action. It doesn't have to be just one observation. It can include many observations, like several people or groups over different times, all within the same study. When researchers study many cases, it's often called cross-case research. When they study just one case, it's called within-case research.

Case studies are used a lot in both the social sciences (like history or psychology) and the natural sciences (like biology or physics).

What is a Case Study?

There are many ways to define case studies. Most experts agree that a case study involves looking very closely at a topic in its real-life setting. It's about understanding something deeply.

For instance, a case study of the French Revolution would look at France before and after the revolution. This shows how even a single "case" can involve multiple observations over time.

When people study many cases, they often call it cross-case research. When they study just one case, it's called within-case research.

One expert, John Gerring, says a case study is "an intense study of a single unit or a small number of units... to understand a larger group of similar units." He explains that case studies help us understand unique details, while other research methods might focus on comparing many things.

Gerring also points out that the main thing that makes case studies different is that they use information from one case. But they still try to explain things that apply to a wider group of similar situations.

How Case Studies Are Designed

Just like other research methods, there isn't one single way to design a case study. Case studies can use at least four main types of designs:

• Some designs start without a specific theory in mind. They let the information guide them.
• Other designs focus on whether it's a single-case study or a multiple-case study.
• A third type looks at how people create their understanding of reality.
• Finally, some designs aim to find "anomalies" or things that don't fit existing ideas.

Even though these designs can be quite different, researchers often combine them. While case studies can explain single events, they often aim to give new ideas about a larger group of similar events.

Choosing and Structuring Cases

When choosing cases for a study, researchers usually look for ones that represent the topic well. They also look for cases that show differences in the things they are interested in. Sometimes, an average or typical case might not give the most information. It can be more helpful to pick subjects that are interesting, unusual, or show a situation very clearly.

Choosing cases randomly might work for studies with many subjects. However, for studies with only a few subjects, random choice can lead to problems. It might pick cases that don't represent the topic well or don't give much information.

Instead, cases should be chosen if they are expected to provide a lot of useful information. For example, outlier cases (those that are extreme or unusual) can often reveal more than typical cases. A case might also be chosen because it's simply very interesting or because the researchers know a lot about it already.

Experts John Gerring and Jason Seawright list seven ways to choose cases:

• Typical cases: These cases show a common relationship. They represent the larger group, and the study looks deeply within the case.
• Diverse cases: These cases show a range of differences in the important factors. They represent the full group of cases.
• Extreme cases: These cases have a very high or very low value for a specific factor compared to others.
• Deviant cases: These cases don't fit existing theories or common sense. They are extreme and challenge what we already know.
• Influential cases: These cases are very important to a theory (like Nazi Germany in studies of fascism).
• Most similar cases: These cases are similar in almost every way, except for the one thing the researcher is interested in.
• Most different cases: These cases are different in almost every way, except for the one thing the researcher is interested in.

For finding new ideas, it's often helpful to use deviant cases or extreme cases.

Other experts, like Arend Lijphart and Harry Eckstein, identified five types of case study designs based on what the research aims to do. Alexander George and Andrew Bennett added a sixth:

• Atheoretical (or descriptive) case studies: These just describe a case very well, without trying to build a new theory.
• Interpretive case studies: These use existing theories to explain a specific case.
• Hypothesis-generating case studies: These aim to find new ideas, variables, or ways things cause each other.
• Theory testing case studies: These check if existing theories are correct and how widely they apply.
• Plausibility probes: These check if new ideas or theories seem reasonable.
• Building block studies: These aim to find common patterns across different cases.

Some researchers warn against "selecting on the dependent variable". This means you shouldn't only look at cases where something happened if you want to understand why it happened. For example, to understand why wars start, you should also look at times when wars did not start. However, some qualitative researchers disagree, saying it can be useful for creating new theories.

Why Case Studies Are Useful

Case studies are often seen as a great way to come up with new ideas and theories. They are very helpful for understanding unusual cases or situations that don't fit the norm. For example, Charles Darwin's theory of evolution came from his travels and observations, which were like case studies.

Case studies also help in defining concepts clearly. The ideas used in qualitative research (like case studies) tend to be more precise than those in quantitative research. Case studies add rich details and can give a very clear picture of what's happening in a specific situation. They are good at explaining outcomes in individual cases, which is harder for other methods.

Case studies can help check if arguments explaining common patterns are believable. They are also good for understanding those unusual or "deviant" cases.

By providing detailed knowledge and descriptions, case studies can fully explain how things cause each other. This can be harder to do in studies that look at many cases at once. They can show how different parts of a cause-and-effect chain connect to produce an outcome.

Case studies of situations that don't fit existing theories can help us understand why. They can also show the limits of a theory. Case studies are useful when things are complex, like when many different paths can lead to the same result, or when past events strongly influence future ones. They can also identify what conditions are needed or not needed for something to happen.

Sometimes, qualitative research (like case studies) is needed to figure out if a situation is truly random or not. So, good quantitative research often includes a qualitative part.

Challenges of Case Studies

Some experts, like Gary King, Robert Keohane, and Sidney Verba, have pointed out challenges with case studies. They suggest that having only a few observations makes it harder to figure out how different factors cause effects. It also increases the risk of errors or that an event was just random. They argue that qualitative research might struggle to determine which of many factors truly links a cause to an effect.

However, other scholars disagree. They argue that qualitative research, especially using methods like "process-tracing," can make strong conclusions even with a small amount of data.

Another challenge mentioned is that case studies might not easily apply to everyone or everything. Because they look at a small number of cases, it can be hard to be sure that the chosen cases represent a larger group. But some experts, like Bent Flyvbjerg, argue against this idea.

Since small-N research (like case studies) doesn't use random sampling, researchers must be careful to avoid bias when picking cases. A common criticism is that cases are chosen because they fit what the researcher already believes, which can lead to biased results. It can also be hard to measure how strong a cause-and-effect relationship is in a case study.

Case Studies in Teaching

Teachers often create case studies to use in classrooms. This is called a "teaching case study" (you might also hear about the case method or casebook method). For example, as early as 1870, at Harvard Law School, a professor named Christopher Langdell started using real court cases to teach contract law. This became the main way law was taught in the United States.

Engineering students participate in a case study competition.

Outside of law, teaching case studies are popular in many fields, from business to science. The Harvard Business School is famous for developing and using teaching case studies. Teachers create these cases with specific learning goals in mind. They often come with extra materials like financial reports, timelines, short biographies, or even videos.

Teaching case studies are also becoming more popular in science education. They cover different areas of biology and physical sciences. The National Center for Case Studies in Teaching Science offers many teaching case studies for use in both university and high school classes.

See also

In Spanish: Estudio de caso para niños

• Analytic narrative
• Casebook method
• Case method
• Case competition
• Case report
• Process tracing