Where is the evidence that that happens more in the US than elsewhere?

What is the margin of error on those browser stats? I doubt a 1% drop from one month to the next is statistically significant.

Even if it is, it was inevitable that there would be a drop. Only IE users get the choice screen and it would be incredible if they all chose IE, so some people are going to switch from IE to something else. A 1% drop sounds extremely small to me, but I'm not sure how far the choice screen has rolled out yet.

No, they solve very different problems. Something like Huggle needs to work out if a given edit can be almost guaranteed *not* to be vandalism (usually because the editor is on a whitelist), everything else gets shown to a human. The important thing for something like Huggle is making it easy for humans to review edits, not judging the edits automatically in any way. Something like ClueBot needs to work out if it can almost guarantee that a given edit *is* vandalism. They are very different.

In that paper, you say you think high-recall (ie. low false negatives) should be preferred to high-precision (low false positives) since it reduces the chance of a reader seeing a vandalised version. I disagree. You underestimate the harm caused by losing editors that get annoyed when their legitimate edits are reverted by a bot. The upcoming feature, Flagged Revisions ( http://en.wikipedia.org/wiki/Wikipedia:Flagged_revisions ), will provide a much better way of preventing readers from seeing vandalised versions while not costing us useful editors.

If the world doesn't want Wikipedia, they are more than welcome to stop reading it. In truth, however, it seems the world very much wants Wikipedia, since it is the 5th most popular website in the world (by unique visitors per month, if memory serves).

Officially, vandalism is defined as edits made in bad faith. If you are trying to improve the article but are an idiot (which includes people that don't realise their own bias), that isn't vandalism, it's just idiocy. It is only if you are editing with the intention of making the article worse that you are vandalising.

Huggle and Twinkle are tools to help humans deal with vandalism. AntiVandalBot and ClueBot, etc., are bots that deal with (the most obvious) vandalism themselves. They are very different things.