Introduction: Evidence and evaluation in social policy

What counts as evidence in social policy, and how evidence does, or perhaps more often, does not, influence policy-making, have become central questions in the last 20 years. The evidence-based medicine movement gathered momentum in the 1980s and 1990s (Sackett et al. 1997), creating a framework for the assessment of research in that field and how it might led to a more robust basis for clinical decision-making, and even health policy. This led to policymakers, especially the New Labour government in the UK, suggesting that the ideological and interest-based politics of the past were now to be jettisoned in favour of an approach that was based instead on a pragmatic, ‘what works’ basis instead (Davies et al. 1999).