Marcia - 12:29 am on May 11, 2007 (gmt 0)

Polysemic words and it's part of keyword co-occurrence, which is what that whole thing is based on. That's why phrases work much better than single terms.

That does not necessarily have anything whatsoever to do with spam, and one word tacked on to a phrase can trigger stats for lack of information gain for the phrase. Nothing less, nothing more. And the system isn't based on a pre-fixed lexicon, it generates the taxonomy based on co-occurrence figures.