Developers of new web browsing software that flags questionable claims or outright lies on the web hope it will become a valuable tool to deal with the misinformation that litters the Internet.

But observers say Dispute Finder, an experimental browser extension developed by Intel, and the many websites that already aim to debunk online rumours and falsehoods face an enormous task. It isn't as easy as simply telling someone they're wrong.

Once installed, Dispute Finder highlights in red what it determines are disputed claims on websites, then offers users links to alternative points of view and evidence to back them up.

"It's important to be aware when something you're reading is not the only opinion, when there is another point of view worth paying attention to," says California-based Intel researcher Rob Ennals.

"The real problem is, when you don't realize something is disputed, you don't realize there are other points of view and you might not be aware you've wandered into a dispute."

The current version of the software relies entirely on users to identify disputed claims, provide evidence and point the software to other instances of that claim on the web, so right now there's still not much content being highlighted.

Eventually, Ennals says users who input claims will be able to train the software to seek out examples and continue to flag new content as it's posted. And, as the software becomes more popular, more claims will be catalogued.

He says real people are in a better position to determine whether a claim is in dispute than any computer and he brushes aside suggestions that doing so might just provide another forum for bogus assertions.

"The good thing is that if something is disputed enough that people will care, the chances are that someone is going to care enough to mark it as disputed," says Ennals.