Comparing tagging vocabularies among four enterprise tag-based services

We compare four tagging-based enterprise services, which respectively stored bookmarks to webpages and documents, to people, to blog entries, and to hierarchically-structured activity records. Analysis of user data and tag data showed relatively small overlaps in tags used. Conventional normalization strategies produced only modest improvement. These results suggest difficulties in combining exploratory searches across multiple social-tagging services. We recommend strategies for cross-service tag integration at the points of tag storage and tag search, rather than at the conventional point of tag entry. We close with a research agenda around this strategy. © 2007 ACM.