The Magenta Book provides a comprehensive overview of evaluation in government: its scoping, design, management, use and dissemination, as well as the capabilities required of government evaluators. It provides new material on the evolving approaches and methods used in evaluation; and emphasises the value of evaluation in providing evidence for the design, implementation and review stages of the policy cycle. 

The Book is written for the policy, delivery and analysis professions; all of which are responsible for securing and using good evidence. 

Evaluation should be built into an intervention’s design and delivery from the earliest stages. High quality evaluation evidence can enable decision-makers to better target their intervention; reduce delivery risk maximise the chance of achieving the desired objectives; and increase our understanding of what works. Routine, high-quality evaluation is part of a culture of continual improvement and should be core to the work of all government departments. Without robust, defensible evaluation evidence, government cannot know whether interventions are effective or even if they deliver any value at all.