THE CASE STUDY :
When they read of a suicide bomber in the Middle East, many people wonder what it is about the terrorist’s personality or background that leads to such behavior. To answer this question, psychologists might conduct a case study. In contrast to a survey, in which many people are studied, a Case Study is an in-depth, intensive investigation of a single individual or a small group. Case studies often include psychological testing, a procedure in which a carefully designed set of questions is used to gain some insight into the personality of the individual or group (Gass et al., 2000;Addus, Chen, & Khan, 2007).
When case studies are used as a research technique, the goal is often not only to learn about the few individuals being examined but also to use the insights gained from the study to improve our understanding of people in general. Sigmund Freud developed his theories through case studies of individual patients. Similarly, case studies of terrorists might help identify others who are prone to violence. The drawback to case studies? If the individuals examined are unique in certain ways, it is impossible to make valid generalizations to a larger population. Still, they sometimes lead the way to new theories and treatments for psychological disorders.