Two thought provoking articles on the utility of ontologies and folksonomies as methods of categorizing data:

• Clay Shirky’s presentation (Ontology is Overrated: Categories, Links, and Tags) examines problems with our attempt to classify and standardize data on the World Wide Web.

• Adam Mathes paper (Folksonomies - Cooperative Classification and Communication Through Shared Metadata) focuses on user-created metadata, where users of documents and media create metadata for their own individual use that is shared throughout a community.

These issues are relevant to the categorization of taxonomic and systematic data.