A relatively stable tag cloud emerges quickly when you have multiple users freely contributing tags. For the popular URL tagging site del.icio.us, a stable tag pattern emerges after 100 users bookmark the site. (Folksonomy). In a study, Adam Mathes has shown that the distribution of tags in a tag cloud follows a power law. There are a few tags used by very many users, a large number of tags used by only a few users, and a very large number of tags used by just one or two users (Folksonomies: Tidying up Tags?). Marieke Guy and Emma Tonkin surveyed two tagging sites, Flickr and del.icio.us, and found similar results. Two power curves, one linear and one logarithmic, from that study and published in Folksonomies: Tidying up Tags? are reproduced below:
Tagging, as a means of classification, improves with scale. As more users contribute, tags with shared meaning are repeated while tags with less shared meaning are relegated to the “long tail” of the curve. For our library patrons, we were interested in both popular tags and tags found in the long tail. Popular tags in a tag cloud capture the shared “aboutness” of a work, while less frequent tags capture the idiosyncrasies of a work. For example a patron once needed images of drug use. The catalog did not return any hits on the subject of drug use. A book in our collection, though, may have only one image of drug use. If so, then no Library of Congress Subject heading, a formal taxonomy, would be assigned to it. This information could get recorded with the folksonomy, in the long tail of the power curve for tags describing that work.
Folksonomies have both advantages and disadvantages over using a more traditional hierarchical taxonomy. Folksonomies are flexible and self-moderating. Unlike a taxonomy, a folksonomy is inclusive by letting the user participate and is often cheaper. Detractors are quick to note that folksonomies are chaotic and imprecise. Ambiguous and inexact tags can hinder searching while overly personalized and misspelled tags can make it even harder. The challenge then is how to maximize the potential of folksonomies while minimizing the disadvantages?
