The Case Study Research Method

Definition and Different Types

Man doing a case study


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A case study is a research method that relies on a single case rather than a population or sample. When researchers focus on a single case, they can make detailed observations over a long period of time, something that cannot be done with large samples without costing a lot of money. Case studies are also useful in the early stages of research when the goal is to explore ideas, test and perfect measurement instruments, and to prepare for a larger study. The case study research method is popular not just within ​the field of sociology, but also within the fields of anthropology, psychology, education, political science, clinical science, social work, and administrative science.

Overview of the Case Study Research Method

A case study is unique within the social sciences for its focus of study on a single entity, which can be a person, group or organization, event, action, or situation. It is also unique in that, as a focus of research, a case is chosen for specific reasons, rather than randomly, as is usually done when conducting empirical research. Often, when researchers use the case study method, they focus on a case that is exceptional in some way because it is possible to learn a lot about social relationships and social forces when studying those things that deviate from norms. In doing so, a researcher is often able, through their study, to test the validity of the social theory, or to create new theories using the grounded theory method.

The first case studies in the social sciences were likely conducted by Pierre Guillaume Frédéric le Play, a 19th-century French sociologist and economist who studied family budgets. The method has been used in sociology, psychology, and anthropology since the early 20th century.

Within sociology, case studies are typically conducted with qualitative research methods. They are considered micro rather than macro in nature, and one cannot necessarily generalize the findings of a case study to other situations. However, this is not a limitation of the method, but a strength. Through a case study based on ethnographic observation and interviews, among other methods, sociologists can illuminate otherwise hard to see and understand social relations, structures, and processes. In doing so, the findings of case studies often stimulate further research.

Types and Forms of Case Studies

There are three primary types of case studies: key cases, outlier cases, and local knowledge cases.

  1. Key cases are those which are chosen because the researcher has ​a particular interest in it or the circumstances surrounding it.
  2. Outlier cases are those that are chosen because the case stands out from other events, organizations, or situations, for some reason, and social scientists recognize that we can learn a lot from those things that differ from the norm.
  3. Finally, a research may decide to conduct a local knowledge case study when she or he has already amassed a usable amount of information about a given topic, person, organization, or event, and so is well-poised to conduct a study of it.

Within these types, a case study may take four different forms: illustrative, exploratory, cumulative, and critical.

  1. Illustrative case studies are descriptive in nature and designed to shed light on a particular situation, set of circumstances, and the social relations and processes that are embedded in them. They are useful in bringing to light something about which most people are not aware.
  2. Exploratory case studies are also often known as pilot studies. This type of case study is typically used when a researcher wants to identify research questions and methods of study for a large, complex study. They are useful for clarifying the research process, which can help a researcher make the best use of time and resources in the larger study that will follow it.
  3. Cumulative case studies are those in which a researcher pulls together already completed case studies on a particular topic. They are useful in helping researchers to make generalizations from studies that have something in common.
  4. Critical instance case studies are conducted when a researcher wants to understand what happened with a unique event and/or to challenge commonly held assumptions about it that may be faulty due to a lack of critical understanding.

    Whatever type and form of case study you decide to conduct, it's important to first identify the purpose, goals, and approach for conducting methodologically sound research.