Yes I know … this is not about MPEG-7 and multimedia, but on the other hand its very interesting Some months ago I started to analyze the structure and usefulness of folksonomies (see here or wikipedia). Especially I was interested in methods for tag similarity computation and the extraction of structure from the chaos of tags and resources. Today I finished an interesting little project, which allows me to create a tag network out of samples taken from del.icio.us. The shown image (click to enlarge) shows a network generated from a list of popular tags from Dec. 28th 2007 in the afternoon. The color of the edges indicates the amount of similarity. Note that the used method does not result in a symmetric measure and therefore an undirected graph, but is normalized based on the source tag and is visualized as digraph.

The similarity of tags is based on the co-ocurrence analysis published by Peter Mika in Ontologies are us: A unified model of social networks and semantics. The visualization has been done with graphviz. The sample from del.icio.us has been taken by monitoring the RSS feed for recent additions.