Scientometrics: Untangling the topics
  Measuring science is based on comparing articles to similar others. However, keyword-based groups of thematically similar articles are dominantly small. These small sizes keep the statistical errors of comparisons high. With the growing availability of bibliographic data such statistical errors can be reduced by merging methods of thematic grouping, citation networks and keyword co-usage. 
Adam Szanto-Varnagy, Peter Pollner, Tamas Vicsek, Illes J. Farkas
cs.DL cs.SI physics.data-an physics.soc-ph