The Folksonomy meme has been bouncing around the blogosphere for a couple of weeks. The idea is to categorize information (such as bookmarks or photos) by user-defined keywords, often called tags. This is especially powerful when combined with a social/collaborative component, such as in the popular web apps del.ici.ous and Flickr.
The old-school alternatives are the taxonomy and the controlled vocabulary. Here, an analyst will examine the information space and come up with good categories. Changing the categories later is not possible or expensive. Examples are the Yahoo! directory and anything ever done in the library sciences.
Folksonomies are messy, emergent, bottom-up, cheap and conceptually simple. Taxonomies are clean, well-designed, top-down, expensive and conceptually complex.
I hazard a guess that most of the Semantic Web crowd is, like me, firmly in the ”˜well-designed metadata’ camp. Our vocabularies and ontologies are designed by experts, then handed down to the users. We are not at ease with the idea of users creating their own categorization schemes. If we’ve learned anything from experience, then that the average user is unable to get a subclass realtionship right. A bunch of sloppily assigned tags will not be useful for inferencing.
This is something the ‘well-designed metadata’ crowd has never understood — just because it’s better to have well-designed metadata along one axis does not mean that it is better along all axes, and the axis of cost, in particular, will trump any other advantage as it grows larger. And the cost of tagging large systems rigorously is crippling, so fantasies of using controlled metadata in environments like Flickr are really fantasies of users suddenly deciding to become disciples of information architecture. …
Any comparison of the advantages of folksonomies vs. other, more rigorous forms of categorization that doesn’t consider the cost to create, maintain, use and enforce the added rigor will miss the actual factors affecting the spread of folksonomies. Where the internet is concerned, betting against ease of use, conceptual simplicity, and maximal user participation, has always been a bad idea.
Betting on the Semantic Web is betting against ease of use, conceptual simplicity, and maximal user participation. And I don’t see how ontologies and the RDF data model stand even the slightest chance in this particular area.
This is something we’ll have to find an answer to.