The first stage of a case study typically involves detailing a case history, usually by interview, although other methods are often used in conjunction. Case history information can include the person’s record in education, employment, their family details, SES, and relationships. A detailed account of their experiences relevant to the issue being investigated is also made at this point (e.g., severe social deprivation, illness, criminal behaviour etc.). As the study progresses additional information is gathered on these variables.

Information in a case study is gathered by many different methods, which depend on the type of information required by the investigation. These can include psychological tests, in-depth unstructured interviews and even physiological tests (e.g., Blood tests, Brains scans, etc).

Often, case studies investigate people that are about to undergo a unique experience that could produce valuable insights into a particular issue. E.g., Gregory & Wallace (1963) investigated SB whose sight was restored after being blind (almost) from birth. Not only were his visual experiences studied, but also his emotional reactions to his progress.

Freud’s psychoanalytic theory was based on numerous case histories of his patients.