In psychological research, understanding the design of studies is essential for assessing the validity of the results. Researchers often use various methods, including observational studies, experiments, and case studies. Each of these methods has its advantages and disadvantages depending on the research question being addressed. One particular approach is the use of case studies, which provide in-depth analysis of a single individual or group over a period of time.
Which of the following is a primary limitation of case study research compared to other methods?