The ODI Bridging Research and Policy project aims to increase understanding of linkages between development research, policy and practice and develop simple tools for researchers and policy makers to promote evidence-based policy that contributes to poverty reduction, alleviation of suffering or the saving of lives. Research and policy defy neat separation but can be conceptually distinguished by their goals and methods; research produces knowledge (whether by, as examples, action-research or academic study); policy aims for continuity or change of a practice (stretching from the statements on intent to the development of policy in practice). In this paper we appraise current models of knowledge utilisation and policy making, as well as other literature that sheds light on the research/policy linkages, and offer an integrated approach to help investigate further.