Case study evaluations - US General Accounting Office

This guide from the US General Accounting Office outlines good practice in case study evaluation and establishes a set of principles for applying case studies to evaluations.

The paper outlines new ways of thinking about case studies and examines the methodology necessary to get the best from a case study analysis.


"This methodology transfer paper on case study evaluations describes how GAO evaluators could use case study methods in performing our work. It describes six applications of case study methods, including the purposes and pitfalls of each, and explains similarities and differences among the six. This paper presents an evaluation perspective on case studies, defines them, and determines their appropriateness in terms of the type of evaluation question posed." (GAO, 1990)


  • What Are Case Studies? 13
    • What Is Meant by “a Case Study”? 15
    • Some Common Benefits Expected From Case Study Evaluations 23
    • Instance Selection in Case Studies 25
  • Case Study Applications 37
    • Illustrative 37
    • Exploratory 40
    • Critical Instance 45
    • Program Implementation 48
    • Program Effects 54
    • Cumulative 57
    • Design Decisions and Case Study Applications 62
  • Data Collection and Analysis 63
    • Data Collection 63
    • Data Analysis 67
    • Handling Multisite Data Sets 70
    • Basic Models for Data Analysis 73
    • Pitfalls and Booby Traps 74
    • Where to Go for More Information 78
  • Summary 79
    • What Are Case Studies? 79
    • When Are Case Studies Appropriately Used in Evaluation? 79
    • What Distinguishes a Good From a Not-Good Case Study? 80
    • Impartiality and Generalizability 84


US General Accounting Office (1990), Case Study Evaluations. Retrieved from:

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