Date Added: Jul 2009
In tagging systems users can annotate items of interest with freeform terms. A good understanding of the usage characteristics of such systems is necessary to improve the design of current and next generation tagging systems. To this end, this work explores three aspects of user behavior in CiteULike and Connotea, two systems that include tagging features to support online personalized management of scientific publications. First, this study characterizes the degree to which users re-tag previously published items and reuse tags: 10 to 20% of the daily activity can be characterized as re-tagging and about 75% of the activity as tag reuse.