In another MOOC she took run by a University of Pennsylvania professor, a half-dozen teaching assistants shepherded student discussion online and cheating was much less pervasive, she said.

WSJ: Web Classes Grapple With Stopping Cheats

Cathy Cheal, senior academic technology officer at San Jose State University in California, which recently accepted several MOOCs for credit, said the key to avoiding cheating online is to structure courses so students are constantly engaged and have to answer questions every few minutes.

WSJ: Web Classes Grapple With Stopping Cheats

Another technique is to encourage customers to police suppliers: eBay, an online marketplace, hugely reduced cheating by getting buyers to rank sellers.

ECONOMIST: Schumpeter

"No real athlete has to look up the definition of cheating, " Tygart said, according to excerpts of the interview posted online.

CNN: STORY HIGHLIGHTS