When University of Central Florida junior Nicole Nissim got stumped in trigonometry, she checked out what was showing on YouTube.
Nissim typically scours the video-sharing website for clips of bands and comedy skits. But this time she wasn't there to procrastinate on her homework. It turned out YouTube was also full of math videos. After watching a couple, the psychology major said, she finally understood trig equations and how to make graphs.
"I was able to watch them at my own pace, and if I didn't get a concept, I could easily rewind it," she said. "It was a lot clearer once I watched the video."
YouTube is perhaps best known for its cavalcade of homemade performances and TV clips, but like Nissim, many people are turning to it for free tutoring in math, science and other complicated subjects.
Math videos won't rival the millions of hits garnered by laughing babies, but a YouTube tutorial on calculus integrals has been watched almost 50,000 times in the last year. Others on angular velocity and harmonic motion have more than 10,000 views each.
The videos are appealing for several reasons, said Kim Gregson, an Ithaca College professor of new media. Students come to the videos when they're ready to study and fully awake, which is not always the case in 8 a.m. calculus classes. And they can watch the videos as many times as they need until they understand.
Viewer comments reflect that. On tutorials posted to YouTube by the not-for-profit Khan Academy, for example, reactions include "Now why couldn't my calc instructor explain it that simply?" and "I was just about to leave my physics course. You saved me." One viewer declared, "You are god of mathematics!!!"
What's creator Salman Khan's trick? Keeping it simple, he said. He takes a laid-back approach, focuses on a single concept and keeps the videos to a digestible 10 minutes. He said he purposely did not create clips featuring himself standing at a whiteboard. He wanted something more akin to sitting next to someone and working out a problem on a sheet of paper.
"If you're watching a guy do a problem [while] thinking out loud, I think people find that more valuable and not as daunting," said Khan, a California hedge fund manager by day and math geek by night.
