The purpose of a case study is to study intensely one set (or unit) of something—programs, cities, counties, worksites—as a distinct whole. A case study is a useful mechanism for evaluating programs, if it is used appropriately and if it is done well. A case study is particularly useful for evaluating unique programs, programs with unique outcomes, and programs carried out in turbulent or unpredictable environments. It is well suited to programs of which at least part of the object is to learn from the process.

As with any evaluation, the keys to effective use of a case study are to design the data collection effort with care, and to create a clear record of the methods used to perform the data collection and analysis. Also, as is true of any evaluation, the data must support the findings.

This guide includes instructions on:

• How to do a case study
• When to do a case study
• Data collection
• Data analysis and interpretation