More than three years ago, Mark Zuckerberg of Facebook trumpeted a plan to share data with researchers about how people interacted with posts and links on the social network, so that the academics could study misinformation on the site. Researchers have used the data for the past two years for numerous studies examining the spread of false and misleading information.
But the information shared by Facebook had a major flaw, according to internal emails and interviews with the researchers. The data included the interactions of only about half of Facebook’s U.S. users — the ones who engaged with political pages enough to make their political leanings clear — not all of them as the company had said. Facebook told the researchers that data about users outside of the United States, which has also been shared, did not appear to be inaccurate.