A new generation of relational charts for comparative assessment of citation impact.

A common problem in comparative bibliometric studies at the meso and micro level is the differentiation and specialization of research profiles of the objects of analysis at lower levels of aggregation. In this study, institutional profile clusters are used to examine which level of the hierarchical subject classification should preferably be used to build subject-normalized citation indicators. It is shown that a set of properly normalized indicators can serve as a basis of comparative assessment within and even among different clusters, provided that their profiles still overlap and such comparison is thus meaningful. Using the example of 24 European universities, a new version of relational charts is presented for the comparative assessment of citation impact.