Mark Zuckerberg Explains How Facebook Plans to Fight Fake News

Mark Zuckerberg late Friday outlined several steps Facebook Inc. is testing to fight misinformation, an acknowledgment that the social network could be doing more to avoid its proliferation.

Facebook is looking to label certain stories as false, build tools to classify misinformation and work with fact-checking groups, Mr. Zuckerberg, chief executive and co-founder, said in a post.

"We take misinformation seriously," Mr. Zuckerberg wrote. "We know people want accurate information."

Mr. Zuckerberg's comments Friday go significantly beyond his previous statements in recognizing the seriousness of the issue, and seek to quell steady criticism.

In the past week, Mr. Zuckerberg has defended Facebook against claims that fake news on the site distorted public discourse about the U.S. presidential election. Two days after the election, Mr. Zuckerberg said that the notion that Facebook helped tip the election in favor of Donald Trump was "a pretty crazy idea."

In a lengthy post last weekend, Mr. Zuckerberg played down the prevalence of fake news on the site--accounting for less than 1% of global content--and said that Facebook's role isn't to be "arbiters of truth."

On Friday, Mr. Zuckerberg reiterated that misinformation is a small part of Facebook content, but that it takes this problem seriously. Mr. Zuckerberg said the disclosure about the steps was unusual for Facebook because it doesn't share specifics about works in progress.

The first and most important step is to rely on technology to better classify misinformation and "detect what people will flag as false before they do it themselves," Mr. Zuckerberg said. Another step is to make it easier for users to report fake stories, he said. Facebook has long relied on users to flag objectionable content, including fake news.

Facebook is turning to outside groups for help in fact-checking, Mr. Zuckerberg wrote. It is also exploring a product that would label stories as false if they have been flagged as such by third-parties or users, and then show warnings to users who read or share the articles.

Facebook earlier this week announced it would bar fake-news sites from using the company's ad-selling tools. Mr. Zuckerberg said he is looking into "disrupting the economics" of sites that traffic in fake information.

Mr. Zuckerberg reiterated that Facebook doesn't want to become an arbiter of truth itself.

"The problems here are complex, both technically and philosophically," he wrote. "We believe in giving people a voice, which means erring on the side of letting people share what they want whenever possible."

Write to Deepa Seetharaman at Deepa.Seetharaman@wsj.com