Evolution of the percentage of edits made by active users in Wikipedia

Power of the few vs. wisdom of the crowd: Wikipedia and the rise of the bourgeoisie has used a history dump of English Wikipedia (58 millions of editions, 4,7 millions of pages). To process this data the have used a powerful environment based in Hadoop. The have calculated the number of edits made and the changes in content between edits (counting words, not lines). Users has also been classified by number of edits, and the editions have been grouped by types of users (from very active to sporadic).