The latest PMPA Report, in conjunction with the National School of Government, with contributions from Janet Grauberg, Peter M. Jackson, Andrew Gray, Wayne Parsons, Annette Boaz, Louise Shaxson and Miles Parker. This is a collection of essays focusing on the current debate about the nature of evidence based policy and the process of academic and practitioner exchange that underpins it. Analysis and use of evidence is a subject which is of interest to all policy makers in government, as well as academics, consultants and commentators. These essays endeavour to look at issues such as ‘what is evidence’, ‘whose evidence is it’, ‘what are the conditions for evidence to make an impact’ and ultimately ‘what needs to change to make things better’.