Luis von Ahn, PhD

Screen shot 2011 07 08 at 11.42.53 pm
known as one of the pioneers of crowdsourcing. He is the founder of the company reCAPTCHA, which was sold to Google in 2009.

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Highest Rated Comments

vonahn1913 karma

vonahn1082 karma

I see what you did there.

vonahn781 karma

This :)

vonahn746 karma

It's not.

vonahn658 karma

Ron Swanson.

vonahn621 karma

By pissing off the user!

vonahn605 karma

Because they don't motivate you to keep going! We spend a lot of effort making Duolingo addictive -- we think the hardest part about learning anything on your own is motivation.

vonahn564 karma


vonahn550 karma

OVERLOOKS (you only have to type one correctly!)

vonahn511 karma