Comparative case studies

This guide, written by Delwyn Goodrick for UNICEF, focuses on the use of comparative case studies in impact evaluation.

The paper gives a brief discussion of their use and then outlines when it is appropriate to use them. It then provides step by step guidance on their use for an impact evaluation.


"A case study is an in-depth examination, often undertaken over time, of a single case – such as a policy, programme, intervention site, implementation process or participant. Comparative case studies cover two or more cases in a way that produces more generalizable knowledge about causal questions – how and why particular programmes or policies work or fail to work.

Comparative case studies are undertaken over time and emphasize comparison within and across contexts. Comparative case studies may be selected when it is not feasible to undertake an experimental design and/or when there is a need to understand and explain how features within the context influence the success of programme or policy initiatives. This information is valuable in tailoring interventions to support the achievement of intended outcomes."


  • Comparative case studies: a brief description
  • When is it appropriate to use this method?
  • How to conduct comparative case studies
  • Ethical issues and practical limitations
  • Which other methods work well with this one?
  • Presentation of results and analysis
  • Example of good practices
  • Examples of challenges


Goodrick, D., (2014), Comparative Case Studies, UNICEF. Retrieved from:


'Comparative case studies ' is referenced in: