Controlled vocabularies and tags: An analysis of research methods

Social tagging has become increasingly common and is now often found in library catalogues or at least on library websites and blogs. Tags have been compared to controlled vocabulary indexing terms and have been suggested as replacements or enhancements for traditional indexing. This paper explored tagging and controlled vocabulary studies in the context of earlier studies examining title keywords, author keywords and user indexing and applied these results to a set of bibliographic records from PubMed which are also tagged on CiteULike. Preliminary results show that author and title keywords and tags are more similar to each other than to subject headings, though some user or author supplied terms do match subject headings exactly. Author keywords tend to be more specific than the other terms and could serve an additional distinguishing function when browsing.