In many areas of the welfare state, there is a growing emphasis on 'evidence-based policy and practice'. Against this background, this edited book provides a hard-hitting and deliberately provocative overview of the relationship between evidence, policy and practice, how policy is implemented and how research can and should influence the policy process. It critiques the notion of 'evidence-based practice', suggesting instead a more inclusive idea of 'knowledge-base practice', based in part on the lived experience of service users. Written by leading policy analysts and researchers, it will be of interest to everyone in health and social care policy, practice and research.