The increasing emphasis on the need for evidence-based policy indicates the continuing influence of the 'modernist' faith in progress informed by reason. Although the rationalist assumptions of evidence-based policy making have been subject to severe challenge from constructivist and post-modernist perspectives, it is argued that the attempt to ground policy making in more reliable knowledge of 'what works' retains its relevance and importance. Indeed, its importance is enhanced by the need for effective governance of complex social systems and it is argued that 'reflexive social learning' informed by policy and programme evaluation constitutes an increasingly important basis for 'interactive governance'. The expanded use of piloting of new policies and programmes by the current UK Government is considered to provide limited scope for evaluation to derive reliable evidence of whether policies work. There is a need for greater clarity about the role of evaluation in situations where piloting essentially constitutes 'prototyping'. More emphasis should be placed on developing a sound evidence base for policy through longterm impact evaluations of policies and programmes. It is argued from a realist position that such evaluation should be theory-based and focused on explaining and understanding how policies achieve their effects using 'multi-method' approaches.

No abstract

The renewed emphasis in the UK on 'evidence-based policy making' has sharpened the focus on the utilization debate in the evaluation community. Traditionally, the emphasis is placed on methodological concerns but this article argues for a sharper focus on the underpinning theoretical bases of policy evaluation, both in terms of its role in policy making and in terms of the substantive theories which inform policy development and implementation. In particular, the article seeks to assess the implications of complexity theory for our theoretical assumptions about policy systems. It is argued that, together with 'new institutionalist' thought and recent work on policy implementation structures, notions of complexity have substantial ramifications for the way in which we approach policy evaluation, given the contemporary concern to address 'cross-cutting' social problems through 'joined-up' policy initiatives. It is suggested that our thinking about evaluation reflects the broader reaction against 'modernist' conceptions of the role of social science in our quest to change and improve the world.

The credentials of the evidence-based policy movement appear to be increasingly subject to challenge based on research that has highlighted the limits on the use of evidence in policy making. However, moves towards a more 'realistic' position of evidence-informed policy making risk conflating prescription with description and undermining a normative vision of better policy making. This article argues that we need to review the ideas that underpin our thinking about evidence-based policy making, and move beyond the territory of instrumental rationality to a position founded upon two intellectual pillars: our developing knowledge about complex adaptive systems; and ideas from a pragmatist philosophical positionespecially those of John Dewey -about social scientific knowledge and its role in guiding action to address social problems. This leads us to a conception of 'intelligent policy making' in which the notion of policy learning is central.

Public sector reforms throughout OECD member states are producing a new model of 'public governance' embodying a more modest role for the state and a strong emphasis on performance management. In the UK, the development of performance management in the context of the 'new public management' has been primarily 'top-down' with a dominant concern for enhancing control and 'upwards accountability' rather than promoting learning and improvement. The development of performance management and evaluation in local government in the UK has been conditioned by external pressures, especially reforms imposed by central government, which have encouraged an 'instrumental-managerial' focus on performance measurement. The new Labour government's programme of 'modernizing local government' places considerable emphasis on performance review and evaluation as a driver of continuous improvement in promoting Best Value. However, recent research has indicated that the capacity for evaluation in local government is uneven and many obstacles to evaluation exist in organizational cultures. Local authorities need to go beyond the development of review systems and processes to ensure that the capacity for evaluation and learning is embedded as an attribute of 'culture' in order to achieve the purpose of Best Value.