Technorati's most recent State of the Blogosphere is about tags and tagging. For those of you not in the know, tags are basically subject headings for blog entries, allowing a blogger to apply one or more tags to a given post so that it can be grouped thematically with others similarly tagged. Thus for example if you were really into Formula One racing all of your posts about that topic could be tagged "Formula One," so that instead of wading through all of your posts you or whoever read your blog could simply call up all of the ones having to do with F1 racing.
Tags are actually not all that new a concept to blogging -- various blog interfaces such as Movable Type have had them for years -- but as of the beginning of 2005 Technorati started tracking tags, and as a result their usage has skyrocketed since, from a virtually neglible amount of bloggers tagging their posts to one-third of all blogs entries since January (about 25,000,000) sporting tags or some other form of categorization. Even the folks at Technorati are astonished at how quickly this phenomenon has mushroomed. Jeff Jarvis himself recently made the switchover to tags at Buzzmachine, and he's been happy as a clam about it ever since.
I'm of two minds on tagging blog posts. While it is nice to be able to explore the content of someone's blog by subject heading, my inner librarian worries about some of the potential pitfalls of self-applied tags. To wit:
1. Tags are not we librarians call a "controlled vocabulary," which means the issue of synonymous subject headings are not addressed. If I tag one post under Politics and another under World News, even if thematically similar these entries will not show up together, and as a result a reader could easily miss out on posts that could be of great interest or use to him/her. While this may not make a huge difference on most individual blogs (whose total amount of tags might run in the dozens), when these tags are picked up on Technorati -- which is currently tracking over a million tags -- the chances of guessing all of the possible synonymous or related subject headings in use become infinitesimally small.
2. Tags are self-applied. I'm not about to pull a Foucault here, but when it comes to categorization the author is usually not the best authority on what subject headings to apply to his/her work, as they frequently confuse what they want the work to be about with what it actually is about. Case in point: we had a professor who had recently written a book and wanted us to catalog it per his specifications, which included about three times the normal amount of subject headings that a standard 200-page scholarly monograph usually gets. He assumed that just because he touched on a certain topic -- however briefly -- that the book's catalog entry should reflect this, when in fact the totality of the work is considered when deciding which subject headings apply.
While self-application is of course unavoidable for something like blogging, and under most circumstances the brevity of the standard blog post doesn't invite the same potential for overcategorization as a library book, awareness of the fact that Technorati is now tracking tag usage has no doubt already fostered a parallel dynamic at the aggregate level. One of the reasons that our professor wanted his book to be "tagged" with as many subject headings as possible is that he wanted it to turn up in the maximum amount of searches as possible by other scholars. Given what happened early in Web history with the gaming of META tags in order to skew internet search engine results, it is hard to imagine that some bloggers aren't doing precisely the same thing with tags and thus distorting legitimate attempts by bloggers to navigate the 'sphere by subject headings.
3. Tags reinforce the notion of a "one note" blogosphere. This is perhaps the most contentious of the three, because whether this is a bad thing or not depends entirely on your conception of how the 'sphere should ideally be. There is a very strong prevailing wisdom that blogs should be focused and to-the-point -- not surprisingly, "one note" blogs that stay mostly within the boundaries of a single area of expertise tend to fare better in the rankings than those which do not. Tags reward this behavior insofar as they encourage "one note" posts. How do you categorize a long and rambling post which interweaves the kind of day you're having with the state of the world and perhaps includes a funny link or two to cheer people up who happen to be similarly blue on that particular Thursday?
This can also lead to the process-driven mischaracterization of posts, where a blogger feels the need to tag everything he or she writes (this sort of overlaps with #2). Sure, one can always file the miscellaneous posts under Miscellaneous, but such a tag would suggest -- at least to my mind -- a lack of quality that might keep potential readers away, especially if all of your best stuff tends to defy easy description. Maybe this is less of an issue for a blog devoted to Mac OS X, but say for the blog of aspiring writer the application of tags can seem a little artificial or forced. Granted, no one is forcing the latter to tag his or her posts, but as more and more blogs in the 'sphere embrace tagging we may reach a point where not using tags will effectively ghettoize your blog.
All of this having been said, I still think tagging is a useful tool. And let's face it, the folks at Technorati are no dummies -- although right now they're eschewing any attempts to make sense of or bring order to the million-plus tags they're currently tracking, it's still fairly early in the game yet. I wouldn't be terribly surprised if in the coming months we began to see the evolution of either some kind of controlled vocabulary of tags or at the very least an automatic thesaurus which suggested related tags as you browsed a certain subject heading. While I agree up to a point that blogging works best when it is permitted to find its own way, there are times when the embryonic discipline of blogology (?) could stand to heed of a little of the hard-earned wisdom of librarians, who have been struggling to categorize a universe of knowledge ever exploding outwards ever since a scribe pushing wedges into clay in Mesopotamia first wondered how the hell he was going to keep track of all his tablets.
UPDATE: Well, color me bashful -- Technorati already suggests synonymous or related tags when you search. Good for them! I'm not sure how thorough it is, but it's a start. And for a lively and learned examination of the debate over controlled vocabularies versus what people are now calling "folksonomies" check out Clay Shirky's post at Corante.