The Australian Journal of Public Administration, vol. 67, no. 1, pp. 1–11 doi:10.1111/j.1467-8500.2007.00564.x RESEARCH AND EVALUATION Three Lenses of Evidence-Based Policy Brian W. Head 1 University of Queensland This article discusses recent trends to incorporate the results of systematic research (or ‘evi- dence’) into policy development, program evaluation and program improvement. This process is consistent with the New Public Management (NPM) emphasis on efficiency and effective- ness. Analysis of evidence helps to answer the questions ‘what works? and ‘what happens if we change these settings?’ Secondly, some of the well known challenges and limitations for ‘evidence-based’ policy are outlined. Policy decisions emerge from politics, judgement and debate, rather than being deduced from empirical analysis. Policy debate and analysis involves an interplay between facts, norms and desired actions, in which ‘evidence’ is diverse and contestable. Thirdly, the article outlines a distinction between technical and negotiated approaches to problem-solving. The latter is a prominent feature of policy domains rich in ‘network’ approaches, partnering and community engagement. Networks and partnerships bring to the negotiation table a diversity of stakeholder ‘evidence’, ie, relevant information, interpretations and priorities. Finally, it is suggested that three types of evidence/perspective are especially relevant in the modern era – systematic (‘scientific’) research, program man- agement experience (‘practice’), and political judgement. What works for program clients is intrinsically connected to what works for managers and for political leaders. Thus, the prac- tical craft of policy development and adjustment involves ‘weaving’ strands of information and values as seen through the lens of these three key stakeholder groups. There is not one evidence-base but several bases. These disparate bodies of knowledge become multiple sets of evidence that inform and influence policy rather than determine it. Key words: evidence-based policy, policy development, performance, program management In many of the mature democracies, the recent ground-swell of interest in ‘evidence-based policy’, on the part of both government offi- cials and social researchers, represents both an opportunity and a challenge. For public man- agers and political leaders, the opportunity is apparent for continuous improvement in policy settings and program performance, on the basis of rational evaluation and well-informed debate of options. The prospect of mutual benefits for managers, researchers and citizens is alluring. This is the modern promise of evidence- based policy improvement, albeit the attempt to link the social sciences and public policy has a much older lineage in the history of progressive reform movements. 2 The social sciences and public decision-makers have not always had close and cordial relations; indeed, there has been a history of mutual distrust between these sectors during the last two centuries. However, scientific and technical knowledge has been greatly prized in the evolution of the modern state, initially because of its links to economic growth and national defence, and later to ad- dress the aspirations for social improvement by the citizens. Social sciences have been valued for their contribution to understanding and in- fluencing social development and well-being. Democratic decision-makers have increasingly aspired to anchor many of their social reform programs in the ‘relevant’ and ‘usable’ knowl- edge provided by the social sciences. C  2008 The Author Journal compilation C  2008 National Council of the Institute of Public Administration Australia