Ideas worth spreading

Massive-scale online collaboration

1,828,003 views | Luis von Ahn • TEDxCMU

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.

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.

This talk was presented to a local audience at TEDxCMU, an independent event. TED's editors chose to feature it for you.

Read more about TEDx.

Learn a new language with Duolingo, a free, collaborative online tool.

About the speaker

Luis von Ahn

Educational equity technologist

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Crowdsourcing pioneer and Duolingo CEO Luis von Ahn builds systems that combine the skills of humans and computers to take on large-scale problems neither can solve alone.

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This talk was presented to a local audience at TEDxCMU, an independent event. TED's editors chose to feature it for you.

Read more about TEDx.

Learn a new language with Duolingo, a free, collaborative online tool.