Magenta Book
The Magenta Book is HM Treasury’s guidance on evaluation for central government policies, programmes and projects. It sets out a comprehensive framework for planning, designing, managing and using evaluation to improve decision-making and strengthen accountability. Emphasising that evaluation should begin early and be embedded throughout the policy lifecycle, the guidance advocates proportionate, high-quality approaches that support learning before, during and after implementation.
The publication covers evaluation scoping, methods, data collection, governance, quality assurance, dissemination and capability development. It reinforces the importance of combining process, impact and value for money evaluations to understand not only whether an intervention worked, but how, for whom and at what cost. New content includes expanded guidance on Test and Learn approaches, benefits management, value for money evaluation, and the appropriate use of artificial intelligence within evaluation practice.
Designed for policymakers, analysts, finance professionals and delivery teams, the Magenta Book promotes evaluation as a core element of effective public investment, helping organisations generate robust evidence, improve programmes iteratively and build a stronger evidence base for future policy and project decisions.