"Real-time corrections do have some positive effect, but it is mostly with people who were predisposed to reject the false claim anyway," said R. Kelly Garrett, lead author of the study and assistant professor of communication at Ohio State University.

"The problem with trying to correct false information is that some people want to believe it, and simply telling them it is false won't convince them."

For example, the rumor that President Obama was not born in the United States was widely believed during the past election season, even though it was thoroughly debunked.

The prospect of correcting falsehoods like this online before they have a chance to spread widely has obvious appeal, Garrett said.

In fact, it has already been attempted: A team from Intel and the University of California, Berkeley, developed Dispute Finder, a plug-in for web browsers that was released in 2009 and would alert users when they opened a webpage with a disputed claim. That project has ended, but Garrett said similar efforts are under way.

"Although the average news user hasn't encountered real-time correction software yet, it is in the works and I suspect it will see more widespread use soon," he said.