The New School of Ontologies is just so off the mark. Not that social classification isn't valuable, but a folksonomy is *not* an ontology. And facets...my goodness. The article reads like a jumble of classification buzzwords stirred once and regurgitated.

Ontologies are semantically-connected nodes - there's meaningful types of relationships between terms (has-a, is-a, requires, and lots lots more). Free tagging doesn't generate any semantic relationship at all.

It's interesting as the folksonomy meme drives more people to talk about IA issues how little many people know about IA concepts...