Before the Internet, coordinating more than 100,000 people, let alone paying them, was essentially impossible. But now with the Internet, I've just shown you a project where we've gotten 750 million people to help us digitize human knowledge.

The question that motivates my research is, if we can put a man on the Moon with 100,000 [people], what can we do with 100 million?

It's hard to think of a time when I'm not working, but when that is the case, I like to travel and eat good food.

One fact we're particularly proud of is that there are more people learning languages on Duolingo in the US than there are people learning languages in the entire US public school system.

Together with my advisor, Manuel Blum, I co-invented CAPTCHAs, or computer-generated tests that humans are routinely able to pass but that computers have not mastered (they are the squiggly computer letters that are prevalent across the web).

Before the Internet, coordinating more than 100,000 people, let alone paying them, was essentially impossible. But now with the Internet, I've just shown you a project where we've gotten 750 million people to help us digitize human knowledge.

In 2011, after spending a couple of years working at Google, I decided that I wanted to dedicate myself to helping to transform education. I was particularly inspired by my upbringing in Guatemala, a poor country where high-quality educational opportunities are limited to those who have money.