Thanks to Steve Greenlaw for pointing me to Clay Shirky’s article Ontology is Overrated: Categories, Links, and Tags. This is a fantastic piece that serves to explain the difference between ontological and folksonomic classification approaches. You should read the whole thing, but the gist is that for centuries we’ve been forced to categorize information ontologically because of the physical-ness of information objects (books, papers, etc.). Because a thing can only be one place at one time, it can only be placed in one category at one time–thus we get library systems like the LOC subject guide. Ultimately, this fails to acknowledge that information objects can actually inhabit one or many categories at a time–and that often (if not always) the decision about what category an object should be placed into in a ontological hierarchy is an entirely subjective process.

The essence of a book isn’t the ideas it contains. The essence of a book is “book.” Thinking that library catalogs exist to organize concepts confuses the container for the thing contained.

The categorization scheme is a response to physical constraints on storage, and to people’s inability to keep the location of more than a few hundred things in their mind at once. Once you own more than a few hundred books, you have to organize them somehow. (My mother, who was a reference librarian, said she wanted to reshelve the entire University library by color, because students would come in and say “I’m looking for a sociology book. It’s green…”) But however you do it, the frailty of human memory and the physical fact of books make some sort of organizational scheme a requirement, and hierarchy is a good way to manage physical objects.

Enter the internet and hypertext. Suddenly, we no longer need to think about information as physical objects, but rather as bits of data that can be tagged endlessly depending on the needs of the user. Where once we had a hierarchy (out of a need to physically organize objects and, thus, ideas) we now have a web of links which can be manipulated and filtered in an infinite number of ways.

It’s a slightly different topic, but this reminds me of endless work I’ve spent over the years trying to organize information on Web pages. Shirky’s diagrams of how information was arranged hierachically and how that hierarchy quickly devolves in a world of hypertext, reminds me of many site maps I’ve drawn over the years. What starts as an attempt to systemically organize content into a clear, branched map ends up a Web of dotted lines and arrows.

Ultimately, the folksonomic approach (or the ideals it embraces) needs to extend beyond tagging and searching. We need to be rethinking the way we’re presenting content altogether. In a way this is what RSS is about–breaking content up into smaller chunks that can be consumed and filtered in endless ways. And when RSS is wedded with open tagging in a service like del.icio.us, the possibilities become very exciting. What will be really interesting, I think, is when we see mainstream Web sites attempt to deliver content with these ideals in mind.

Shirky correctly points out that this approach to information delivery is really about differences in fundamental philosophy:

It comes down ultimately to a question of philosophy. Does the world make sense or do we make sense of the world? If you believe the world makes sense, then anyone who tries to make sense of the world differently than you is presenting you with a situation that needs to be reconciled formally, because if you get it wrong, you’re getting it wrong about the real world.

If, on the other hand, you believe that we make sense of the world, if we are, from a bunch of different points of view, applying some kind of sense to the world, then you don’t privilege one top level of sense-making over the other. What you do instead is you try to find ways that the individual sense-making can roll up to something which is of value in aggregate, but you do it without an ontological goal. You do it without a goal of explicitly getting to or even closely matching some theoretically perfect view of the world.

Ultimately, I believe that this is about so much more than how we choose to tag information on the Web. When people believe there is a “perfect view of the world” there will always be those who attempt to control what that view is. Perhaps the hierarchies came as a result of the physical-ness of information, but, like it or not, the hierachies have now invaded every aspect of our lives. We don’t just arrange books and information this way, we arrange power this way. There are institutions and people out there that will believe the folksonomic approach is inherently disruptive (which it is) and thus, threatening (which it also is — to these institutions and people). Whether or not they will be able to stop the force of this movement remains to be seen.