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.

[Captchas] are not only annoying, but they kill 10 seconds of your time.

This sounds strange to many people, but I work out for exactly 16 minutes every day, and do so at maximum speed by running 2.5 miles. This keeps me healthy without taking up too much time so I can stay focused on other things. It's one of the most efficient things I do each day.

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).

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

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

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.