Jimmy Wales wrote:
My research (conducted in December) showed that half the edits by logged in users belong to just 2.5% of logged in users. It would be extremely interesting to run tests to compare "edit dispersion" for new articles, old articles, heavily edited articles, highly watched articles, heavily trafficked articles, etc.
Those sound like plausible numbers, but I think your methodology is somewhat overstating the cohesiveness: The "drive-by editors" who are the least associated with an identifiable Wikipedia community are the users who haven't even bothered to go so far as to create a user account, which you explicitly exclude from your count.
-Mark