Facebook may be the largest news source in the world based on sheer number alone, but recent revelations show a distortion in the process for determining what becomes so-called “trending topics.” Documents obtained by the Guardian show how Facebook actually decides what becomes top “news” for its over 1 billion users.

Allegations of editorial bias against conservative news organizations earlier this week prompted US Senate commerce committee chair, John Thune, to call for a congressional inquiry.  Despite claims to the contrary by the company, top topics are curated by human hands, and not machines. Of course, this introduces the factor of bias. The trending topics are usually listed on the side of the browser in Facebook’s desktop version, and a small editorial team ultimately decides what makes it to that coveted spot.

According to the Guardian:

  • A team of news editors working in shifts were given instructions on how to “inject” or “blacklist” stories into the trending topics module, with a lot left to the discretion of the editors.
  • The editorial team can push a topic to the top spot if users create something that attracts a lot of attention.
  • All of the trending news stories come from only 10 news sources.

“Trending Topics uses a variety of mechanisms to help surface events and topics that are happening in the real world. In our guidelines, we rely on more than a thousand sources of news – from around the world, and of all sizes and viewpoints – to help verify and characterize world events and what people are talking about,” said Justin Osofsky, Facebook’s vice-president of global operations.

 “The intent of verifying against news outlets is to surface topics that are meaningful to people and newsworthy. We have at no time sought to weight any one viewpoint over another, and in fact our guidelines are designed with the intent to make sure we do not do so,” he added.