Citations and their use as indicators in science policy: studies of validity and applicability issues with a particular focus on highly cited papers

This dissertation aims at contributing towards the discussion on the use of citations as indicators. A particular focus is directed towards highly cited papers. Because citation distributions are extremely skewed in which most publications are poorly cited or not cited at all and a few publications are very highly cited, it is clear that this phenomenon has to be taken into account when constructing and using citation indicators. It is thus of particular interest to analyse patterns of highly cited papers. This then leads on to a number of studies of the methodological basis and validity of citation indicators.