Measuring science is based on comparing articles to similar others. However, keyword-based groups of thematically similar articles are dominantly small. This keeps statistical errors high. With the growing availability of bibliographic data these statistical errors can be reduced by merging methods of thematic grouping, citation networks and keyword co-usage networks.
Scientometrics: Untangling the topics
Adam Szanto-Varnagy, Peter Pollner, Tamas Vicsek, Illes J. Farkas