Abstract
Recent reductions in research budgets have led to the need for greater selectivity in resource allocation. Measures of past performance are still among the most promising means of deciding between competing interests. Bibliometry, the mea surement of scientific publications and of their impact on the scientific community, assessed by the citations they attract, provides a portfolio of indicators that can be combined to give a useful picture of recent research activity. In this state-of-the- art review the various methodologies that have been developed are outlined in terms of their strengths, weaknesses and par ticular applications. The present limitations of science indica tors in research evaluation are considered and some future directions for developments in techniques are suggested.