%V 81
%N 2
%L eprints1097
%X In this paper we investigate the nature and structure of the relation between imposed classifications and real clustering in a particular case of a scale-free network given by the on-line encyclopedia Wikipedia. We find a statistical similarity in the distributions of community sizes both by using the top-down approach of the categories division present in the archive and in the bottom-up procedure of community detection given by an algorithm based on the spectral properties of the graph. Regardless of the statistically similar behaviour, the two methods provide a rather different division of the articles, thereby signaling that the nature and presence of power laws is a general feature for these systems and cannot be used as a benchmark to evaluate the suitability of a clustering method.
%I IOPscience
%K PACS: 89.75.Hc Networks and genealogical trees; 89.75.Fb Structures and organization in complex systems; 89.75.-k Complex systems
%A Andrea Capocci
%A Francesco Rao
%A Guido Caldarelli
%D 2008
%T Taxonomy and clustering in collaborative systems: the case of the on-line encyclopedia Wikipedia
%R 10.1209/0295-5075/81/28006
%J EPL (Europhysics Letters)
%P 28006