The New York Times reports:

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.

“This undermines trust researchers may have in Facebook,” said Cody Buntain, an assistant professor and social media researcher at the New Jersey Institute of Technology who was part of the group of researchers, known as Social Science One, who have been given the user activity information.

“A lot of concern was initially voiced about whether we should trust that Facebook was giving Social Science One researchers good data,” Mr. Buntain said. “Now we know that we shouldn’t have trusted Facebook so much and should have demanded more effort to show validity in the data.” [Continue reading…]