Ontologies vs. Folksonomies
Ontologies provide structure and a standard for tagging and searching, while folksonomies provide for an emergent system for tagging things.
It is argued - though currently the arguments are filtering only slowly into the academic literature - that folksonomies are preferable to the use of controlled, centralised ontologies [e.g. 259]. Annotating Web pages using controlled vocabularies will improve the chances of one's page turning up on the 'right' Web searches, but on the other hand the large heterogeneous user base of the Web is unlikely to contain many people (or organisations) willing to adopt or maintain a complex ontology. Using an ontology involves buying into a particular way of carving up the world, and creating an ontology requires investment into methodologies and languages, whereas tagging is informal and quick. One's tags may be unhelpful or inaccurate, and no doubt there is an art to successful tagging, but one gets results (and feedback) as one learns; ontologies, on the other hand, require something of an investment of time and resources, with feedback coming more slowly. And, crucially, the tools to lower the barriers to entry to controlled vocabularies are emerging much more slowly than those being used to support social software .