I noticed that David Weinberger had Many-to-Many: reviewed RawSugar, which is prompting me to add a few comments.

I spoke recently with the founder, Ofer Ben-Schachar, who suggests that we are going to drown in the flat tagspace that we are creating, and that one obvious solution is to create hierarchical aggregations of tags. He points out that we have grown used to this idea in e-commerce sites, where the class of "cameras" is broken into various makes, price ranges, or types.

I argued with him, suggesting that these domain schemas -- like the way discussions about wine naturally fall into vintage, region, country of origin, and grape -- are a general case, but that there is no way that a system like RawSugar, or a group of people, can develop such schemas for all sorts of things. Or to agree, in many cases, how these classifications work. Consider the difficulties in classifying music: what the hell do you say Broken Social Scene is? And most of the things that people fiddle around with on the web are not clearly about just one thing, or only linked to one schema.

He showed me an example of how RawSugar could provide a means to decomplexify a universe of discourse for one reasonably well-defined group: those interested in bicycling in the San Francisco area. He worked with several groups and developed a taxonomy for this universe of discourse, including tags and a hierarchical ordering of them, so that information about trails would be tagged consistently with "rides for kids," "gentle rides," "difficult rides," and so on.

My argument remains the same: I believe that that the approximation and fuzziness of tags is their true value: we don't have to be dead on, but over time, order emerges. I don't buy the idea that we need to have order imposed.

At the same time, there are hundreds, if not thousands of realms where clear-cut natural domain schemas exist: restaurants, wine, and many other examples come to mind. Even music -- leaving aside the fuzziness of music genres -- naturally has artists, labels, albums, tracks, and so on. So there may be a way that RawSugar can worm its way into the tagosphere, and provide value.