It was bound to happen sooner or later. Simple lists are great, weighted lists (or tag clouds) are even better. But as data accumulates, its no longer practical to navigate it through tag lists. Some sort of structure is needed. Back in February I had written about tag-sorting, and how easy it should it should be to cluster tags.
How it works: When you click on a tag, you have the option of exploring different clusters related to the tag. For example, summer has several associated clusters:
Cluster 1: beach, sea, vacation, sand, ocean, june, trip, island, florida, august
Cluster 2: water, lake, boat, river, reflection, rain, window, bridge, fountain, boats
Cluster 3: sky, blue, sun, sunset, clouds, tree, park, trees, white, leaves
Cluster 4: flower, green, flowers, garden, nature, red, yellow, grass, pink, macro
Unlike Clusty (based on Vivismo), there is no effort to name the cluster. Naming requires a much more sophisticated algorithm, and even then, there is a possibility of getting it wrong. Instead Flickr just shows you the tags comprising each cluster. You can do this with tags (show a succint summary of each cluster by showing the tags). Much harder to do this with url’s which is probably one reason that Clusty has to resort to cluster names.
Another design decision was the display of clusters. From time immemorial (ok, well maybe not time immemorial, but definitely since search interfaces have been worked on), researchers/companies have experimented with visual displays of clusters. There is something so visually compelling about the clusters that arrange themselves (as in Grokker.com). And yet, such interfaces have never acheived mass popularity a la Google/Yahoo.
Overall what I like about Clustering on Flickr:
-Clustering tags, not items. I had predicted this a little while back. It makes a lot of sense to cluster tags rather than the items. Its probably much easier (computationally speaking), and easier to understand (from a user perspective) clusters of tags rather than clusters of items (or photos).
-Not trying to automatically generate a name for the clusters. This is once again a good idea. Err on the side of simplicity. And a few example tags do a better job of describing the cluster than a automatically chosen name would. If you look at the findings from Cognitive Psychology, a few exemplars from a category help convey the category better than a prototype (or central tendency – represented by a name can).
-No fancy visual display. Its tempting to use some type of snazzy display to show clusters. Its good that Flickr stayed away from that, at least for a first attempt.
-There is no “More” category: Their clustering algorithm seems to be good enough that there are a small number of clusters. There is no “More” clusters with a whole set of sub-clusters as with Grokker. (This might be because the database is still not that big – this might break down as more and more pictures get added to Flickr.)