LUIS VON AHN, a computer scientist at Carnegie Mellon University, sold one Internet start-up to Google in 2009, and is now on to another. With the new company, Duolingo, he hopes to tap the... Read more
Language does not come naturally to machines. Unlike humans, computers cannot easily distinguish between, say, a river bank and a savings bank. Satire and jokes? Algorithms have great troubl... Read more
All for free After re-purposing CAPTCHA so each human-typed response helps digitize books, Luis von Ahn wondered how else to use small contributions by many on the Internet for greate... Read more