Folksonomy is a term coined by ThomasVanderWal used to describe the BottomUp taxonomy development as done in social networking sites like and as well as others. GeneSmith brought the term forward for wide consumption.

A broad folksonomy is the result of one item being categorized by many people ( is an example). This environment provides the ability to normalize on some of theBottomUp terms. There will be some terms that have many people use to describe one item or many items in the same way. These concentrations of terms can take advantage ofPowerLaws to quickly see the preferred terms for an item or items.

A narrow folksonomy is the result of one person categorizing an item (Flickr is an example). Gaining acceptance or normalization with synonyms is more difficult, but a tool that can offer possible related tags that have more broad acceptance can be a method of building the taxonomy. The tool will most likely begin with a TopDown taxonomy as the guide, but can flourish to embrace a BottomUp perspective if the tool learns as users take advantage of it. In other environments, a tool will simply aggregate the most used similar tags by statistical observation of other users, and suggest them first, so the BottomUp structure grows emergently.

More here:


  • [Ontology of Folksonomy] – Tom Gruber’s paper on the connection of folksonomy to formal ontologies from a Semantic Web perspective.