The magenta book: Guidance for evaluation

This guide, from H M Treasury, is the central guidance for all UK government departments on evaluation.

It focuses on: how evaluations should be designed and managed; outlining some of the different evaluation options available; how evaluation improves policy making; how evaluation results and evidence should be interpreted and presented; and how thinking about evaluation before and during the policy design phase can help to improve the quality of evaluation results.


"All policies, programmes and projects should be subject to comprehensive but proportionate evaluation, where practicable to do so. The Magenta Book is the recommended central government guidance on evaluation that sets out best practice for departments to follow. It is hoped, however, that it will be useful for all policy makers and analysts, including those in local government and the voluntary sector. It presents standards of good practice in conducting evaluations, and seeks to provide an understanding of the issues faced when undertaking evaluations of projects, policies, programmes and the delivery of services. The Magenta Book is not a textbook on policy evaluation and analysis – the field has plenty of such texts. Rather, it is written and structured to meet the specific and practical needs of policy makers and analysts working in public policy."


  • Key issues in policy evaluation 11
  • Identifying the right evaluation for the policy 17
  • Building impact evaluation into policy design 25
  • What practical issues need to be taken into account when designing an evaluation 31
  • The stages of an evaluation 39
  • Setting out the evaluation framework 53
  • Data collection 69
  • Process evaluation, action research and case studies 81
  • Empirical impact evaluation 97
  • Drawing together and reporting evaluation evidence 125


H M Treasury. (2011). The Magenta Book: Guidance for evaluation. UK Government. Retrieved from: