Tags and taxonomy: Together at last!

There's two parts to this story, a new feature and an intellectual level having to do with one of the burning questions of library and information science. I've introduced the intellectual question below, and Abby is going to look at it from her perspective over on LibraryThing's new "ideas" blog Thing-ology.

The Feature. I've reintroduced LC Subject Headings*, those things in library catalogs that look like

Great Britain--History--Stuarts--1603-1714--Fiction

Except on LibraryThing, they get webbed into

Great Britain > History > Stuarts, 1603-1714 > Fiction (15)

This feature shows up in your catalog, but also in a new subject section (eg., subject: Aesthetics), on tag pages (eg., tag: aesthetics) and elsewhere. Note that the subjects are read-only. It might be interesting in the future to allow users to add their own subjects, so long as the difference is tracked.

The intellectual element. Second and more importantly, LibraryThing now provides something that has long been the Holy Grail of certain librarians and information people: a direct, statistically significant comparison between user-created tags and formal, professional classificiations—between "folksonomies" and taxonomies—and in the book space to boot. Every tag now shows related subjects, and every subject shows related tags—all with statistical data shown or a click away.

The issue is a hot one, with a large amount of debate on the relative merits of tags and professional classifications, like the LC subject headings. Are tags better than subjects? Are subjects better than tags? Are tags just a fad? Will tags replace subjects? Are tags evil? Are subjects evil? (Believe me, the idea is out there.) Librarians have become deeply emeshed in the debate, with partisans on both sides. Until now, there hasn't been much in the way of hard data, at least for books. LibraryThing provides that.**

Let the analysis begin! Over the next few weeks, I want to explore the issue. I hope other library and information bloggers will also take it up. If you ask me, the answer is what many of us long suspected—tags can be useful, but they're different. Tags are here to stay, but they're not going to kill professional classification either. In my mind the interesting questions are: When do tags work better? When do they fail? Why? Can tags and subjects work together somehow, or are they eternal enemies?

* In fact, all "Subject Access" (600s) fields, so there will also be National Agricultural Library subjects, Canadian Subject Headings, etc. There is an issue with foreign-language headings which will be fixed together with other LT character set issues.
** I don't want to get bogged down with shortcomings and contemplated impovements here. (Go to the Google Group for that.) Here's a short initial list: (1) There are language issues (above), (2) There are some character-set issues, (3) Because of how LT gets its information, not every work has subjects that could.