What is a case study?

Case Study

What is a case study?

A case study is an investigative observation on a person or even a community. It involves gathering information from various sources about the body in question to draw conclusion on a particular matter (Yin, 2003, p. 10). A case study sources information from aspects in close relation to an individual such as his family members or medical history to comprehend the current condition. It can also be a research project, which attempts to explain the dynamics of a certain historical period of a particular social unit taking into account the behavior of the individual and social phenomena (Yin, 2003, p. 10).

Yin (2009) defines a case study research as a method of inquiry into contemporary phenomenon based on real life issues, and becomes widely applicable where the boundaries between phenomenon and context are not clearly defined.

Reasons for using case study approach

A case study is descriptive and it enables a researcher to interpret qualitative information that could not possibly be analyzed in research laboratories.

Case studies are often used in explaining theories and they enable generation of new ideas. A case study helps relate bits of information regarding an individual to help explain a holistic character. It is therefore useful to psychologists who are usually involved in such all-inclusive traits.


  1. Data collected in case study is more inclusive as it entails a detailed enquiry into a subject, which is not normally the case in other research methods.
  2. Case study is usually so helpful in cases where samples similar to the particular case are not available. In most cases, sensitive body injuries have no related samples and hence case studies are used for diagnosis.
  3. Scientific experiments can be undertaken alongside case study and this makes it able to create hypotheses that can be used for later studies.


  1. Case study is intensive (it concentrates on one side of an occurrence), thus the results of a case study cannot be generalized.
  2. Information collection in a case study can be biased because usually, an individual experimenter undertakes it.

Sources of information for use by a researcher in a case study

A case study relies on extensively searched information that must be factual. This means that the various sources of information identified by the researcher should offer the best opportunity to study and understand the situations under investigation. The researcher conducting a case study may therefore decide to use a primary or a secondary source of information (Patton, 2002, p. 16). While observation, interviews and questionnaires or survey results fall under the category of primary sources, project reports, mystery client reports facility assessment reports and evaluation reports fall under the category of secondary sources. The project reports include quarterly reports, midterm reviews, which are information developed chronologically to enable analysis of the condition at hand (Patton, 2002, p. 16). The primary sources like observation or interview enable the researcher to have direct evaluation of the social phenomena being examined, although its main disadvantage is that it can be biased. Evaluation reports on the other hand describe a program in terms of its success and areas where improvements are required (Patton, 2002, p. 20). Other important sources of data for a case study are from collaterals, which include sources like family and friends. This is mostly used in argumentative matters like custody evaluation, injury claims, and civil suits.


Patton, Michael Q. (2002). Qualitative Research & Evaluation Methods. Thousand Oaks: Sage Publications.

Yin, Robert K. (2003). Case Study Research: Design and Methods. London: Sage Publications.