Human Computation

I thought this was interesting (from the WSJ):

The idea is that because there are many tasks that humans still do better than computers, why not just get people to do them? Often, the best way to do just that is to make a game out of it.

That was the insight of Luis von Ahn, a 28-year-old professor at Carnegie Mellon University who is the creative force behind a Web hit known as the ESP Game, at espgame.org. The site has had more than 130,000 visitors and has lately inspired other researchers to try the same thing.

The game links two random players via the Web. Both are shown the same picture, then have to type in possible keywords to describe what they see. If the keywords match, points are awarded; people have been known to play for hours.

What's really going on, though, is that a previously unlabeled picture collected off the Internet is being given keywords that can be used later to categorize or retrieve it.