This paper is the initial Position Statement of Evidence Synthesis International, a new partnership of organizations that produce, support and use evidence synthesis around the world. The paper (i) argues for the importance of synthesis as a research exercise to clarify what is known from research evidence to inform policy, practice and personal decision making; (ii) discusses core issues for research synthesis such as the role of research evidence in decision making, the role of perspectives, participation and democracy in research and synthesis as a core component of evidence ecosystems; (iii) argues for 9 core principles for ESI on the nature and role of research synthesis; and (iv) lists the 5 main goals of ESI as a coordinating partnership for promoting and enabling the production and use of research synthesis.

This paper argues that evidence-based policy has clearly made a worldwide impact, at least at the rhetorical and institutional levels, and in terms of analytical activity. The paper then addresses whether or not evidence-based policy evaluation has had an impact on policy formation and public service delivery. The paper uses a model of research-use that suggests that evidence can be used in instrumental, conceptual and symbolic ways. Taking four examples of the use of evidence in the UK over the past decade, this paper argues that evidence can be used instrumentally, conceptually and symbolically in complementary ways at different stages of the policy cycle and under different policy and political circumstances. The fact that evidence is not always used instrumentally, in the sense of “acting on research results in specific, direct ways” (Lavis et al., 2003, p. 228), does not mean that it has little or no influence. The paper ends by considering some of the obstacles to getting research evidence into policy and practice, and how these obstacles might be overcome.

A key part of Howard White’s work has been getting policymakers and other development decision-makers to use high-quality evidence to make better decisions. This paper reviews the role of evidence in decision-making and some of the key mechanisms by which this can be achieved. It recognises the many factors other than evidence that influence the decision-making process, and some of the barriers that have to be overcome for high-quality evidence to have a contributory role. The importance of identifying and using appropriate intermediaries is recognised, as is the necessity for clear and accessible communication.