The last decade has seen a growing focus on producing evidence-based policy and practice in governments around the world - with a specific focus on causal evidence of the impacts of a particular policy on outcomes for citizens. The UK is a key example of this, with the establishment of 14 What Works Centres which collate, create and translate evidence in different policy and practice domains. In this book, leaders, researchers and practitioners from these institutions share insights to help understand what has worked so far in the Centres, and what could be done better in future. It offers guidance to policy makers and funders looking to establish new centres, and for academics looking to create similar institutions that can have a practical impact on the improvement of the world around us.