It Depends.

I’ve always liked either/or questions.  My sister and I, whenever we had to ride in the car for days (the mainland never seems quite so big as when you’re driving, in our case, from Michigan to Arizona), would play Death Is Not An Option, only our situations were always pleasant.  The older we got, the more the conversation changed.  Classic example: Tom Cruise vs. Brad Pitt.  There would be actual debate (Cruise looses points for aliens, Pitt for Meet Joe Black), clarification (were we drinking tea or performing espionage?), and then the eventual conclusion.  But, like I said, we got older and the rules changed.  For one, I don’t even like tea.  Anyway, the answer, is, of course, Johnny Depp.  If you were wondering.

So we come to the question of social tagging vs. professional cataloging and classification.  (in this instance, I feel Pitt is social tagging)  Thing is, they both have very strong points and very serious drawbacks.  So we change the rules a little, we combine the two.

There are several key differences between the systems:

• Rules for social tagging are much looser than for subject headings.  You can add as many tags as you want, but subject headings are more specific.  This is a plus for social tagging because you stand a better chance of finding the resource if there are multiple entry points.  However, this kind of thinking often leads one in circles, and it is part of what subject headings can help avoid.  With tagging, there are no ‘broader terms,’ or ‘narrower terms,’ just more options in general.   The long-term effect of repeated social tagging for specific resources would be that the useful tags would float to the top, and the pointless ones would die off–Darwinism.  Subject headings don’t have that luxury.  People living in Hawaii are going to be classed as aliens until someone in charge realizes it’s part of the United States and changes the book.
• The tag is determined by the user. This allows for greater flexibility in regards to the diversity of users.  Dewy Decimal classification, for example, is ridiculously skewed toward white Americans.  If you’re, for example, not a white dude from Minnesota, it’s probably more difficult to follow the chain of thought that puts Hawaiians and Martians in the same category. (admittedly, I’m a white chick from Michigan, and I still find the logic awfully fuzzy.)  So a huge bonus that makes social tagging so accessible is that you can use slang or local terminology (seriously, all examples of Brit Speak as compared to the American Bastardization Of are completely fleeing my brain, but you know what I’m talking about.) to look up your materials.  Subject Headings do help, though, to make sure there are specific places to look for specific materials.  I do find it interesting that at some point, there become accepted slang terms for social bookmarking, the collective edits itself.  The adaptability of the structure is helpful, but would be aided significantly if paired with a stricter framework.
• Tags can be easier to remember.  searching for ‘purple people eaters’ is easier than remembering you have to look for ‘magical creatures, care of’ and then continue on, because you just look up exactly what you need. (and oh my god, has there ever been a more disturbing mental image to drive home the importance of grammar: are the people being eaten purple,  or are the people eaters themselves purple?  never thought about it until I just typed it. ick.)  Being able to remember what you’re looking for when going back is fairly crucial on large projects.  However, again the structure of subject headings proves its worth by making the exact same path to a source available to all users.  It is frequently not just one person who wants to know about local recipes.  Using subject headings, you’d look through Cooking to find a recipe for Loco Moco.  In my tag list it would be under Culinary Experiments Gone Seriously Awry.  In Jenna’s it’d be under Gastrointestinal Bliss.  You can see how I’d miss that if I were only using her tags.  So while I might have a fondness for my easily remembered tag, it would prove useless to a different user.  And while we do want to allow access to resources to be personalized, only using social tags would be far too personal.

There really are a great many benefits to each system, but I think the best option is the third: combine the two.  Live Journal, for example,  now allows you to tag your blog entries, however you want.  But the most useful tags, the ones used in moderated communities where more than one person uses them, are the ones selected from a list.  I think if there were an easy way of users choosing tags, instead of just inventing them, social tagging could really revolutionize catalogs.  As it stands, subject headings rely completly on the assessment done by only a few individuals.  If users as well as catalogers were allowed access to tagging utilities, the results could be remarkable.