# Friday Math Movie - Human Computation

By Murray Bourne, 25 Jul 2008

This week's movie is from Wired.com/PBS.

It features Luis von Ahn who developed the "Captcha" system of reducing spam in Web-based forms. (Captcha are those weird letters that you need to copy into the box before hitting "Submit").

He talks about digitising books using OCR (optical character recognition) and making use of "wasted human cycles" for good. People will read fuzzy words in the books to improve the OCR result.

There's an interesting section on how to improve image search on the Web. This involves getting humans to play a game where they tag an image. You can play this yourself at Gwap.

Update: Gwap is no longer available.

He talks about his Guatemalan heritage, where he became an expert on "beating the system" and this helps him to think of making better use of human computation.

[There is advertising at the beginning of this movie.]

Update: The video is no longer available.

Nice to know there is still a role for humans...

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