Citation measures at the micro level: Influence of publication age, field, and uncitedness

The application of micro-level citation indicators is not without controversy. The procedure requires the availability of both adequate data sets and trusted metrics. Few indicators have been developed to deal specifically with individual assessment. The h-type indices are the most popular category; however, the dependence of h-type metrics on publication age and field makes their application often unjustified. This article studies the effects that publication age and field normalization have on h-type citation values of German Leibniz Prize winners. This data set is exclusive in that it is highly scrutinized for homonyms. Results are compared with other field-normalized citation rates, contributing to the debate on using demarcation versus average citation approaches to evaluate top researchers. © 2012 Wiley Periodicals, Inc.