Tag Clouds Branch Out

For me personally, I have found a few subject headings in the library catalog that have been helpful when I’m researching something, but it’s not a primary strategy I use. I haven’t had much luck searching for or through subject headings themselves but I’ve found subject headings through particular books if I paid attention in the library catalog. I’d venture to bet that’s how most people find subject headings if they’ve ever bothered. (That could be what they’re designed for, rather than browsing, although I haven’t looked into it. )

I recently ran into an attempt over on Davey P’s weblog to use subject headings in a different form, a tag cloud. A tag cloud is a term for the types of visualizations that sites like Flickr, del.icio.us and the like use as a part of their navigation. It seems to have been developed to display info that is unrelated structurally (i.e. not in a tree or whatnot) by popularity of keyword tags - very different from highly structured library subject headings.

A tag cloud gives an overview of the whole system in one visualization. The trade off is that there needs to be a threshold of popularity for the keywords so that the cloud isn’t too overwhelming, and in the library example above “sub-subjects … are collapsed into the parent subject” which seems to make sense for a hierarchical system. It is interesting to know the “popularity” of certain subjects in the library, although that’s probably not what most people are looking for - but it could give clues about what terms are used, and that could be useful. As long as the limitations of this navigation are recognized I think it’s a great additional interface for browsing, particularly if people become more familiar with tag clouds.