When people think about psychology studies, they are most likely to think about studies involving several participants split across a number of experimental and control groups. Studies like this are a good way to investigate the effect of a certain treatment or activity, but they are not always the best option. For example, if a scientist is interested in a specific rare disease, they cannot always find enough people with that disease to participate in a useful study. Similarly, one cannot give a group of participants a rare disease (for obvious reasons) and compare them to a group of participants without that disease. For situations like this, there are case studies.
What is a case study?
A case study is, as the name suggests, a study of a single case. For example, if someone has an extremely rare disease, a group of scientists might conduct a case study of that disease rather than attempting to set up an experimental study. In that case study, the researchers might test the effectiveness of a certain drug in treating that disease and carefully document the response of that participant over time.
Of course, the results seen in that one participant will not necessarily apply to all people with that rare disease. However, if the case study shows promising results, that treatment can then be tested in a larger experimental study. If it does not, it indicates that the treatment is not necessarily effective, at least in people that are similar to the original participant in the case study.
Why are case studies useful in psychology?
When people are still learning about psychology, they might think that group studies showing group effects are always better than individual studies showing individual effects. Of course, there is some truth to this notion, as results obtained from a large number of people are likely to be more generalizable than results obtained from a single person. However, this does not mean that we should discount the importance of individual effects.
Consider the following: In studies looking solely at group effects, individual effects can be masked. In other words, certain statistical quirks can lead to the appearance of a group effect despite the fact that no single individual showed that effect. While this is rare, it is possible. For this reason, it is important to consider individual effects. That is why, even in experimental studies examining groups, it can be useful to examine individual effects within that group. This underlines the value of case studies.
Wrapping up
At the end of the day, there are many good reasons that experimental studies examining groups are the most common types of psychological studies. However, case studies are also extremely valuable, particularly when group experiments are less feasible. Just as psychology is a large topic encompassing a wide variety of factors, both case studies and experimental group studies should be used in the larger overall strategy of psychology research.
