Community Black holes
Interesting stuff from Anjo on some problems he's having with an algorithm to discern weblog communities. It seems his current algorithm works fine until it hits a power node (or what he calls a "core blog").
The core blogs ... act as black holes: once the algorithm hits on one of them it is very difficult to escape.Intuitively (I think) the problem makes a lot of sense. What struck me was that it was based on access to full feeds - I wonder whether the same problem would hold trying to cluster based on subscription lists/OPML?