Is Facebook more than just an online 'echo chamber'?
By Peter Aldhous Facebook is more than just an online echo chamber in which users just repeat views that match their own, according to a new study from the social-media giant’s own data team. “The research suggests that… online social networks actually increase the spread of novel information and diverse viewpoints,” says study leader Eytan Bakshy, discussing the findings on the team’s blog. Clearly, Facebook has a vested interest in distancing itself from the charge that it is fuelling a polarisation of views that some commentators contend is poisoning political debate. But while the new study does question common assumptions about the flow of information through social networks, it seems unlikely to lay this accusation to rest. The analysis comes from an experiment that ran over seven weeks in 2010, while Bakshy was working towards his PhD at the University of Michigan in Ann Arbor. It involved more than 253 million users of Facebook and almost 76 million web addresses (URLs) shared by these people on the site, giving more than a billion unique user-URL pairs. One common problem with studies of social media is that it is difficult to tell whether people share material because they have seen their friends share it, or whether they just happen to be highlighting the same content because they tend to look at the same websites. To control for this, Bakshy and his collaborators at Facebook randomly assigned the user-URL pairs to “feed” or “no feed” conditions. For the latter, any content which shared the URL in question was blocked from that user’s Facebook “news feed” for the duration of the experiment. The researchers also divided the users’ friends into “strong” or “weak” ties, depending on measures including the number of times they sent each other private messages, or how often they were both tagged in the same photo. Not surprisingly, whichever method the researchers used, users were much more likely to share URLs flagged up in individual posts by friends with whom they had stronger ties. However, Facebook users have many more weak ties than strong ones. Cumulatively, the researchers found, most of the information shared on Facebook comes predominately through a user’s weak ties. That’s important, argues Bakshy, because friends with weaker ties are more likely to read and share material that you would not otherwise encounter: “The information they are sharing is more novel.” Maybe so, but without knowing more about the content of what was shared, it is hard to dismiss the charge that Facebook acts as an echo chamber in which people propagate material that chimes with their own views. “I would think it’s more likely that you would selectively share the things from your weak ties that coincide with your view of the world,” says Jennifer Neville of Purdue University in West Lafayette, Indiana, who works on data mining of social media. While the new study certainly isn’t the last word on Facebook’s status as an online echo chamber, it highlights a dilemma facing the site’s developers as they strive to develop algorithms to improve users’ experiences. Filtering material to highlight content posted by close friends should increase the average interest of each user’s personal news feed, but it would also block the flow of novel views and information coming from weaker ties. “It’s definitely a balancing act,” says Bakshy,