A  case study is a type of research that consists of the detailed observation of a single subject or group with the goal of generalizing the results and knowledge obtained. They can be done in many fields; health, education, psychology, social work, business, nursing, human rights , among others. Case study definition and example

Case studies are part of qualitative research ; that is, research that focuses on studying a phenomenon in depth instead of using statistics to draw general conclusions. This type of research can be used for different purposes.

Some of the most common purposes are to create a theory before conducting a more expensive study, to study unusual situations, or to investigate in depth a phenomenon relevant to the researcher.

The most used techniques in case studies are observation and questionnaires, although we can find other methods depending on the discipline in which this research is carried out.

For example, an environmental institution or group of researchers might ask: What are the effects of plastic pollution on whale shark reproduction? In this case, a case study would be “the effects of plastic pollution on whale shark reproduction in the Caribbean Sea.” It can be seen that the study focuses on the whales of the Caribbean Sea, not those that inhabit the world’s oceans. Case study definition and example

Characteristics of a case study

A case study has several characteristics:

A specific case or situation is investigated

The most important characteristic of a case study is that it is the in-depth study of a situation, event or specific case, in such a way that its internal characteristics are mainly taken into account, but also the context in which it occurs.

Variation according to discipline

Depending on the discipline in which this methodology is applied, a case can be defined in different ways.

For example, in psychology a case is usually considered to be a patient with a certain type of mental disorder; in anthropology a case may be a tribe that has not had contact with western society; in biology it can be a population of a certain species. Case study definition and example

Search for understanding

The main intention of the case study is to try to understand all the variables that influence the specific situation under study and how they interact with each other. Although this methodology does not allow establishing causal relationships, it has the following advantages:

• It is cheaper and logistically simple to carry out, since it does not require very large populations or laboratory conditions.
• It allows observing events that only occur naturally, and that cannot be reproduced at will. In this way, previous theories that were only hypothetical until now can be verified.
• It helps to establish some first hypotheses to facilitate future research.
• It allows to study a phenomenon in depth, so that more conclusions can be drawn about it.

What are the objectives of the case study?

In general, the most common objectives of a case study are the following:

• Generalize the knowledge obtained to all similar cases. Case study definition and example
• Explore reality to later formulate a theory.
• Describe what happens in the case.
• Explain the causes that cause it.

Unlike many of the other existing types of research, the case study is inductive; that is, it goes from concrete situations to a general explanation.

However, in order to affirm a cause-effect relationship, it is necessary to supplement this type of research with another of a quantitative type.

How to do a case study? Methodology

The standard definition of case studies considers that they have five main phases:

1- Creation of a research question

The first step in conducting a case study is to ask a research question based on an observation by the researcher. For example: Case study definition and example

• How does pizza consumption affect childhood obesity?

2- Case selection

Second, it is necessary to find a relevant case for the researcher with which to answer the research question. In general, the investigator will choose a case that is relevant to their previous work, or will choose to study a rare event that is suddenly available. For example:

• Case study of the effect of pizza consumption on obesity in a local school in Mexico City.

3- Obtaining the data

After establishing the relevant research questions, the data collection phase begins. Through observation, questionnaires or interviews, the researcher will obtain as much information as possible about the situation he is studying. Case study definition and example

• In our example of the case study on childhood obesity, data such as the frequency of pizza consumption, the weight of the children, frequency of physical exercise, etc. would be taken.

4- Analysis of the collected data

Because qualitative research, such as the case study, does not allow a causal explanation to be established, the data analysis will focus on comparing the research question with the collected data.

At this time, the researcher can decide whether he believes that the data obtained can be extrapolated to other situations or not, in addition to pointing out possible avenues of investigation to learn more about the phenomenon studied. Case study definition and example

• In our example, the incidence of obesity in school children would be analyzed.

5- Creation of the report

Finally, once the data has been collected and analyzed, the researcher will explain the research process chronologically. In addition to talking about the most relevant situations, he will also tell how he has collected the data.

In this way, the researcher will be able to communicate to his readers what he has learned from the case, his conclusions and their validity.

Case study in psychology

In psychology, the case study is a type of research that is carried out especially in the field of mental illness.

Because it is unethical to cause disorders in the laboratory in order to study them, researchers have to learn more about them by studying people who already have them. Case study definition and example

In fact, the one who is considered by many to be the first modern psychologist, Sigmund Freud, based all his theories about the human mind on the study of the cases of patients who came to his office.

Famous case study examples in psychology are Anna O and Little Albert.

Examples of case studies

Phineas cage

Possibly the most famous case study example in history is that of Phineas Gage, a construction worker who was involved in an accident while on a construction site. His skull was pierced by a steel bar that damaged part of his brain, but Gage managed to survive. Case study definition and example

However, this man’s personality completely changed after the accident. Psychologists of the time were then able to study the effect that parts of the brain damaged in the accident had on Phineas’ personality.

This type of research could not have been carried out in any other way, since the brain of a patient cannot be damaged in the laboratory to know the effects of each injury.

For this reason, neuroscience was originally based entirely on case studies, which allowed us to observe this type of phenomenon without having to purposely harm anyone.

Other examples