i202 Fall 2009 School of Information, UC Berkeley

The Clay Shirky article referred to by Marlow et al in the Tagging Paper is makes for highly entertaining reading. Shirky writes about the differences between thinking about professionals doing categorisation to people doing tagging on the web and when it makes sense to do one or the other. He calls this difference 'browse versus search':

'Browse versus search is a radical increase in the trust we put in link infrastructure, and in the degree of power derived from that link structure. Browse says the people making the ontology, the people doing the categorization, have the responsibility to organize the world in advance. Given this requirement, the views of the catalogers necessarily override the user's needs and the user's view of the world. If you want something that hasn't been categorized in the way you think about it, you're out of luck.

The search paradigm says the reverse. It says nobody gets to tell you in advance what it is you need. Search says that, at the moment that you are looking for it, we will do our best to service it based on this link structure, because we believe we can build a world where we don't need the hierarchy to coexist with the link structure.'

And my favorite part (something I hadn't thought of before):

'LiveJournal makes absolutely no attempt to enforce solidarity or a thesaurus or a minimal set of terms, no check-box, no drop-box, just free-text typing. Some people say they're interested in movies. Some people say they're interested in film. Some people say they're interested in cinema.

The cataloguers first reaction to that is, "Oh my god, that means you won't be introducing the movies people to the cinema people!" To which the obvious answer is "Good. The movie people don't want to hang out with the cinema people." Those terms actually encode different things, and the assertion that restricting vocabularies improves signal assumes that that there's no signal in the difference itself, and no value in protecting the user from too many matches.'

And then there's 'Clay Shirky's Viewpoints are Overrated' by Peter Merholz who says that 'Clay's whole argument predicates a black-and-white distinction between evil hierarchy on one side and good tags on the other... And while Clay is right to question hierarchy, and, particularly, Yahoo's less-than-optimal use of it, he neglects to distinguish truly useful forms of professionally-created classification and categorization, which undermines his argument.' And more.

I tend to think that all these grand generalisations are useless without examining a specific case - not just in terms of a person who is looking for something or a person who is tagging something, but both in concert.

Merholz is doing just what he accuses Shirky of (good hierarchy on one side and evil tags on the other) by ending with what he believes will convince us:

'I leave you with this. When considering purchasing an alarm system for my house, I Googled "home security." The amount of noise in those results is startling, because "home" and "security" can mean so many different things. However, using Yahoo!s Directory, I can find all manner of highly relevant items.'