Accepted for publication Sociology of Science Yearbook 2007.Research evaluation has been an essential practice of the regular functioning of the research system (Zuckerman and Merton, 1971; Cole and Cole, 1973). Reputational competition (Merton, 1957; Ben-David, 1971, 1972; Whitley, 2000; Dasgupta and David, 1994) has been shaped by mechanisms of evaluation of research mostly identified with the practice of peer review for journals’ publications (Campanario, 1998 a, b; Cole, 1998). Some of these practices for publishing papers or awarding prizes have been extended to the allocation of the funding for research from governments or intermediary organisations (Chubin and Hackett, 1991; Cole, Rubin and Cole, 1978). More recently, state research evaluation systems (RES)1 have been developed in a number of countries in the context of new public management practices, scarce public funds and increasing accountability requests (Georghiou, 1995), and the allocation of resources for organizations and programs has become more and more connected to the evaluation of research (Geuna and Martin, 2003; Liefner, 2003). Additionally, the dominant ex ante or project appraisal approaches have been complemented by the institutionalisation of retrospective ex post evaluations of research performance2, as the papers by Kneller, Cozzens ands others in this volume discuss.Peer reviewed