The Structure of Collaborative Tagging Systems

Collaborative tagging describes the process by which many users add metadata in the form of keywords to shared content. Recently, collaborative tagging has grown in popularity on the web, on sites that allow users to tag bookmarks, photographs and other content. In this paper we analyze the structure of collaborative tagging systems as well as their dynamical aspects. Specifically, we discovered regularities in user activity, tag frequencies, kinds of tags used, bursts of popularity in bookmarking and a remarkable stability in the relative proportions of tags within a given url. We also present a dynamical model of collaborative tagging that predicts these stable patterns and relates them to imitation and shared knowledge. KEYWORD LIST Collaborative tagging, folksonomy, Del.icio.us, bookmarks, web, sharing. In this paper we analyze the structure of collaborative tagging systems as well as their dynamical aspects. Specifically, through the study of the collaborative tagging system Delicious, we are able to discover regularities in user activity, tag frequencies, kinds of tags used and bursts of popularity in bookmarking, as well as a remarkable stability in the relative proportions of tags within a given url. We also present a dynamical model of collaborative tagging that predicts these stable patterns and relates them to imitation and shared knowledge. We conclude with a discussion of potential uses of the data that users of these systems collaboratively generate.