The End of the Echo Chamber
A study of 250 million Facebook users reveals the Web isn’t as polarized as we thought.
Justin Sullivan/Getty Images.
But there are two reasons why Bakshy’s research should be considered a landmark. First, the study is experimental and not merely observational. Bakshy wasn’t just watching how people react to news shared by their friends on Facebook. Instead, he was able to actively game the News Feed to create two different worlds in which some people get a certain piece of news and other, statistically identical, people do not get that news. In this way, his study is like a clinical trial: There’s a treatment group that’s subjected to a certain stimulus and a control group that is not, and Bakshy calculated the differences between the two. This allows him to draw causal relationships between seeing a link and acting on it: If you see a link and reshare it while some other user does not see the link and does not share it, this means that the Facebook feed was responsible for the sharing.
The other crucial thing about this study is that it is almost unthinkably enormous. At the time of the experiment, there were 500 million active users on Facebook. Bakshy’s experiment included 253 million of them and more than 75 million shared URLs, meaning that in total, the study observed nearly 1.2 billion instances in which someone was or was not presented with a certain link. This scale is unheard of in academic sociological studies, which usually involve hundreds or, at most, thousands of people communicating in ways that are far less trackable.
At the same time, there’s an obvious problem with Bakshy’s study: It could only occur with the express consent of Facebook, and in the end it produced a result that is clearly very positive for the social network. The fact that Facebook’s P.R. team contacted me about the study and allowed me to interview Bakshy suggests the company is very pleased with the result. If Bakshy’s experiment had come to the opposite conclusion—that, say, the News Feed does seem to echo our own ideas—I suspect they wouldn’t be publicizing it at all. (Bakshy told me that he has “a good amount of freedom” at the company to research whatever he wants to look into about the social network, and that no one tells him what to investigate and what to leave alone. The study is being submitted to peer-reviewed academic journals.)
Also, so as not to completely tank the ongoing sales of my brilliant book, I’d argue that Bakshy’s study doesn’t indemnify the modern media against other charges that it’s distorting our politics. For one thing, while it shows that our weak ties give us access to stories that we wouldn’t otherwise have seen, it doesn’t address whether those stories differ ideologically from our own general worldview. If you’re a liberal but you don’t have time to follow political news very closely, then your weak ties may just be showing you lefty blog links that you agree with—even though, under Bakshy’s study, those links would have qualified as novel information. (Bakshy’s study covered all links, not just links to news stories; he is currently working on a follow-up that is more narrowly focused on political content.)
What’s more, even if social networks aren’t pushing us toward news that confirms our beliefs, there’s still the question of how we interpret that news. Even if we’re all being exposed to a diverse range of stories, we can still decide whose spin we want—and then we go to the Drudge Report or the Huffington Post to get our own views confirmed.
Still, I have to say I’m gratified by Bakshy’s study. The echo chamber is one of many ideas about the Web that we’ve come to accept in the absence of any firm evidence. The troves of data that companies like Facebook are now collecting will help add some empirical backing to our understanding of how we behave online. If some long-held beliefs get overturned in the process, then all the better.
Farhad Manjoo is Slate's technology columnist and the author of True Enough: Learning To Live in a Post-Fact Society. You can email him at firstname.lastname@example.org and follow him on Twitter.