Despite progress in some public policy domains, as reported in thefirst half of this book, making a reality of evidence-based policyand practice remains a major challenge. Chapter Two has consideredthe issue of the relationship between evidence and policy making(particularly at the central government level); this chapter isconcerned primarily with the relationship between evidence andfront-line practice.

The literature on research utilisation (for example, Weiss, 1998)tells us that much research appears to have little or no impact onpractice. Many reasons have been cited as to why this is the case.Much of the focus has been on the gaps between researchers andpolicy makers/practitioners. Policy makers and practitioners aresaid to live in a different world to that occupied by researchers –they have different sets of interests and concerns in relation toany research project and hence find it difficult to communicate withone another (Caplan et al, 1975; Higgins, 1978 ; Husen, 1984).Social science knowledge is necessarily imprecise, inconclusive,complex and contingent, whereas policy makers and practitioners, itis argued, can only use knowledge if it is precise, gives clearguidance, and is formulated in sufficiently simple terms to bedirectly applied (Merton, 1957; Lindblom and Cohen, 1979). There arealso practical differences in the ways in which research andpolicy/practice are organised; for example, they operate todifferent timescales and have contrasting dynamics – research isslow while policy situations change quickly. There are alsodifferences in relative status – in the context of centralgovernment policy making researchers are likely to be relativelylow-status in relation to those whom they wish to influence.

Part of the disillusionment of policy makers and practitionersrelates to the hope that research will result in building acumulative knowledge base. One of the key aspirations of socialscientists and policy makers is that as research multiplies,knowledge will converge and produce cumulative findings. However, inreality the opposite often happens (Cohen and Weiss, 1977). Morerecently there has been progress towards developing a cumulativeevidence base in some public service areas (particularly inhealthcare).