Collaborative creation of communal hierarchical taxonomies in social tagging systems

P Heymann, H Garcia-Molina - Stanford, 2006 - heymann.stanford.edu
Background Recently I have been interested in trying to create hierarchical taxonomies from
flat tag data. Tagging systems like del. icio. us, Flickr, and CiteULike tend to have (relatively)
flat tags. This means that while one can easily browse by a tag, like photography, one
cannot as easily see tags which are more or less broad than that tag. It is also difficult to get
a broad overview of what tags exist in these sorts of systems as a result, aside from
frequency based displays like tag clouds.