Tagging is not Library Classification

And it is not intended to be.

One of the most common arguments against folksonomies is that as a classification system, folksonomies are inferior to professional or specialist created taxonomies like those we use in the library system.   Folksonomies, however, were never designed to fulfill the same functions.  According to Stewart Butterfield of Flickr, "The job of tags isn't to organize all the world's information into tidy categories.  It's to add value to the giant piles of data that are already out there."³⁶  

Physical (un)Constraints: The primary distinction between folksonomies and libraries is that libraries developed systems to organize physical objects that can only exist in one place at a time.^{37 38}  Subject categories and subcategories ensure that every object has only one location.³⁹   Folksonomies organize objects that can exist in many places and can be accessed in many ways.⁴⁰  As Clay Shirky concludes, "there is no shelf,"  and it is limiting to classify non-corporeal data as if there were.⁴¹   

Clairvoyance: Classification systems need to imagine how people are thinking, and to predict their needs for the future.⁴²   This requires specialists.  Folksonomies allow non-specialists to come up with their own terms, eliminating the need for anyone to mind read, and allowing for change over time without requiring the entire system to be renovated.  

Demographics: At this point in time, folksonomies are more recreational and personal than research based (although CiteULike, Connotea, and Del.icio.us can be helpful for tracking down serious information).  As Michael Wexler points out, "every popular “tagging” system, to date, has been for consumer fun stuff (Flickr, etc.) and not for real knowledge management."⁴³  For serious research, a library is still the best place to begin.