Preparing a Case Study: A Guide for Designing and Conducting a Case Study for Evaluation Input

When is a Case Study Appropriate?

Case studies are appropriate when there is a unique or interesting story to be told. Case studies are often used to provide context to other data (such as outcome data), offering a more complete picture of what happened in the program and why.

What are the Advantages and Limitations of a Case Study?

The primary advantage of a case study is that it provides much more detailed information than what is available through other methods, such as surveys. Case studies also allow one to present data collected from multiple methods (i.e., surveys, interviews, document review, and observation) to provide the complete story. There are a few limitations and pitfalls however, each of which is described below.

Can be lengthy: Because they provide detailed information about the case in narrative form, it may be difficult to hold a reader’s interest if too lengthy. In writing the case study, care should be taken to provide the rich information in a digestible manner. 

Concern that case studies lack rigor: Case studies have been viewed in the evaluation and research fields as less rigorous than surveys or other methods. Reasons for this include the fact that qualitative research in general is still considered unscientific by some and in many cases, case study researchers have not been systematic in their data collection or have allowed bias in their findings. In conducting and writing case studies, all involved should use care in being systematic in their data collection and take steps to ensure validity and reliability in the study.

Not generalizable: A common complaint about case studies is that it is difficult to generalize from one case to another. But case studies have also been prone to overgeneralization, which comes from selecting a few examples and assuming without evidence that they are typical or representative of the population. Yin, a prominent researcher, advises case study analysts to generalize findings to theories, as a scientist generalizes from experimental results to theories.