"This book provides a critical and long overdue analysis of the contribution of decades of evaluation research to policy making. The text is concise, comprehensive, objective and eminently readable." Philip Jacobs, University of Alberta and the Institute of Health Economics, Canada "In an era of resource constraint the case for improving the way public policy is evaluated gains weight. This wide-ranging book provides an in depth analysis of alternative approaches to evaluation that will be of great interest to both scholars and policy makers." Robin Hambleton, Professor of City Leadership, University of the West of England, Bristol