Clay Shirky’s got a nice, concise post on “folksonomies” on Many-to-Many, which passionately argues that folksonomies have to be better than controlled taxonomies because controlled taxonomies are basically, well, worthless:
The advantage of folksonomies isnÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢t that theyÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢re better than controlled vocabularies, itÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s that theyÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢re better than nothing, because controlled vocabularies are not extensible to the majority of cases where tagging is needed. Building, maintaining, and enforcing a controlled vocabulary is, relative to folksonomies, enormously expensive, both in the development time, and in the cost to the user, especailly the amateur user, in using the system.
Furthermore, users pollute controlled vocabularies, either because they misapply the words, or stretch them to uses the designers never imagined, or because the designers say ÃƒÂ¢Ã¢â€šÂ¬Ã…â€œOh, letÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢s throw in an ÃƒÂ¢Ã¢â€šÂ¬Ã‹Å“OtherÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢ category, as a fail-safeÃƒÂ¢Ã¢â€šÂ¬? which then balloons so far out of control that most of what gets filed gets filed in the junk drawer. Usenet blew up in exactly this fashion, where the 7 top-level controlled categories were extended to include an 8th, the ÃƒÂ¢Ã¢â€šÂ¬Ã‹Å“alt.ÃƒÂ¢Ã¢â€šÂ¬Ã¢â€žÂ¢ hierarchy, which exploded and came to dwarf the entire, sanctioned corpus of groups.
This is only true up to a point. For instance, can you imagine the NHS running a database of medical condition based on a folksonomy? No. That would be silly. There will always be people who rely on controlled taxonomies. What seems important here is the importance of each individual classification. If the classification is basically not that important (as with a holiday photo), a folksonomy is fine – indeed, preferable. When a classification is life-and-death (as with a medical condition) control seems essential.
As a newspaper online, we’re sort of in between. Our stuff isn’t life and death, but if we filed an article about a cabinet minister under “paedophile” we’d be in a certain amount of trouble. So how best to combine the power of folksonomies with the control of taxonomies?