If you get asked to do something that would take place down the road (say you get asked to speak at a conference that's a year away) and you wouldn't want to do it if it were taking place next week, then don't do it. This advice has helped me evaluate the opportunities that I truly want to dedicate my time to and those that I don't.

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.

Because education is such a broad area, I chose to focus on language learning.

I am an early riser, and always wake up between 5 and 6am.

I worked on a number of projects that were used by millions of people and that also served as inspiration to what we now call "crowd-sourcing."

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?

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.