Facebook said on Thursday it will introduce tools to prevent fake news stories from spreading on its platform, a response to rising criticism that it did not do enough to combat the problem during the U.S. presidential campaign.

Facebook is testing several ways to make it easier to report a hoax if you see one on Facebook, which you can do by clicking the upper right hand corner of a post.

The company has also started a program to work with third-party fact checking organizations that are signatories of Poynter’s International Fact Checking Code of Principles. Facebook will use the reports from its community, along with other signals, to send stories to these organizations. If the fact checking organizations identify a story as fake, it will get flagged as disputed and there will be a link to the corresponding article explaining why. It will still be possible to share these stories, but you will see a warning that the story has been disputed as you share.

In the News Feed, reading an article makes people significantly less likely to share it, that may be a sign that a story has misled people in some way. Facebook is going to test incorporating this signal into ranking, specifically for articles that are outliers, where people who read the article are significantly less likely to share it.

Spammers make money by masquerading as well-known news organizations, and posting hoaxes that get people to visit to their sites, which are often mostly ads. So Facebook is trying to reduce the financial incentives. On the buying side Facebook has eliminated the ability to spoof domains, which will reduce the prevalence of sites that pretend to be real publications. On the publisher side, Facebook is analyzing publisher sites to detect where policy enforcement actions might be necessary.

A few weeks ago, Chief Executive Mark Zuckerberg said it was a "crazy idea" that fake or misleading news on Facebook helped swing the election in favor of Republican Donald Trump. But criticism persisted amid reports that people in the United States and other countries have fabricated sensational hoaxes meant to appeal to conservatives.