1.1 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 texts1. Rather, it is written and structured to meet the specific and practical needs of policy makers and analysts working in public policy and explains:
• The important issues and questions to consider in how evaluations should be designed and managed;
• The wide range of evaluation options available;
• Why evaluation improves policy making;
• How evaluation results and evidence should be interpreted and presented; and,
• Why thinking about evaluation before and during the policy design phase can help to improve the quality of evaluation results without needing to hinder the policy process.
1.2 The Magenta Book is complementary guidance to the HM Treasury Green Book2. The Green Book presents the recommended framework for the appraisal and evaluation of all policies, programmes and projects. This framework is known as the "ROAMEF"3 policy cycle, and sets out the key stages in the development of a proposal, from the articulation of the rationale for intervention and the setting of objectives, through to options appraisal and, eventually, implementation and evaluation, including the feeding back of evaluation evidence into the policy cycle. The Magenta Book provides further guidance on the evaluation stage of this policy process and central government departments and agencies should ensure that their own manuals or guidelines are consistent with the principles contained here.
1.3 Evaluation examines the actual implementation and impacts of a policy to assess whether the anticipated effects, costs and benefits were in fact realised. Evaluation findings can identify "what works", where problems arise, highlight good practice, identify unintended consequences or unanticipated results and demonstrate value for money, and hence can be fed back into the appraisal process to improve future decision-making.
The Magenta Book will be useful for:
• policy makers who wish to be able to provide evidence of a policy's effectiveness and value for money;
• anyone commissioning, managing, working, or advising on an evaluation of a policy, project, programme or delivery of a service; and
• those seeking to understand or use evaluation evidence, particularly for the purposes of improving current policies and using that learning for future policy development.
1.4 The Book is divided into two parts.
• Part A is designed for policy makers. It sets out what evaluation is, and what the benefits of good evaluation are. It explains in simple terms the requirements for good evaluation, and some simple steps that policy makers can take to make a good evaluation of their intervention more feasible. It also discusses some of the issues around the interpretation and presentation of evaluation results, especially as they relate to the quality of the evaluation evidence.
• Part B is aimed at analysts and interested policy makers and is therefore more technical. It discusses in greater detail the key steps to follow when planning and undertaking an evaluation and how to answer evaluation research questions using different evaluation research designs. It also discusses approaches to the interpretation and assimilation of evaluation evidence.
1.5 References are provided in the text to supplementary guidance which provides more technical, detailed discussion of key areas4.
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1 For example http://www.socialresearchmethods.net/http://ec.europa.eu/regional policy/sources/docgener/evaluation/evalsed/index en.htm
2 http://www.hm-treasury.gov.uk/data greenbook index.htm
3 ROAMEF stands for 'rationale, objectives, appraisal, monitoring, evaluation, feedback', and is described in more detail in Chapter 1.
4 Supplementary guidance will also provide information about evaluation topics outside the scope of the Magenta Book, for example macro-economic evaluation.