The SCOT(Social Semantic Cloud Of Tags) ontology is to semantically represent the structure and semantics of a collection of tags and to represent social networks among users based on the tags.
Now, the real breakthru of folksonomical-based systems like del.icio.us or flickr is not the lack of structure or commitee-based design in the ontological space, but is the idea that if two people use the same term, it's more probable than they meant the same thing than they meant different things.
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