In this TED video, Luis von Ahn of Carnegie Mellon introduces Duolingo.com, a free online language tutorial site that (in the background) uses your quiz answers to help translate the web. Massive online collaboration.
Along the way, von Ahn explains reCAPTCHA – those two-word “type the mangled words to prove you’re a human” tests found on forms on Facebook, Ticketmaster, and many major sites.
Amazingly, in those tests, one word is from a digital book that computers couldn’t read – the OCR failed. So, when you fill out those reCAPTCHA forms, you’re helping to digitize books. (The other word is truly a test, to cross-check the digital book word.)
The video description:
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 greater good. In this talk, he shares how his ambitious new project, Duolingo, will help millions learn a new language while translating the Web quickly and accurately — all for free.
Here’s the video, “Massive-Scale Online Collaboration“: