How does Facebook decide what to show you?

August 7th, 2013

Going forward, the power of intermediaries like Google and Facebook to decide what news to show you will become critical. I have argued that the ability to include is almost as significant to exclude. Information we don’t see may as well not exist. It is hard to overstate the distorting effect on the marketplace of ideas this control may have. It has often been a mystery of how Google chooses to include, or exclude certain results in search ranks. Companies who file suit against Google, claiming that their rankings were unfair, consistently lose. Google has raised the First Amendment has a defense.

This dynamic is even more acute on Facebook. I have north of 1,500 FB friends. Facebook has decided, in its infinite wisdom, to show me the news updates of certain people, and not others. That decision is driven largely by my decision of whose status updates I click on (and perhaps by who clicks on mine). Facebook has determined who are the people I care about the most. But this comes at a cost. There are lots of people whose important statuses I never see. I’ve had friends get married, graduate from school, move, etc. And I never even knew it. Other people, whom I don’t really know well, but I find their links interesting, frequently flood my feed with personal updates I don’t care about.

Now, Facebook is letting us peek inside their black box with their new window into the news feed.

With so many stories, there is a good chance people would miss something they wanted to see if we displayed a continuous, unranked stream of information. Our ranking isn’t perfect, but in our tests, when we stop ranking and instead show posts in chronological order, the number of stories people read and the likes and comments they make decrease.
So how does News Feed know which of those 1,500 stories to show? By letting people decide who and what to connect with, and by listening to feedback. When a user likes something, that tells News Feed that they want to see more of it; when they hide something, that tells News Feed to display less of that content in the future. This allows us to prioritize an average of 300 stories out of these 1,500 stories to show each day.
The News Feed algorithm responds to signals from you, including, for example:
  • How often you interact with the friend, Page, or public figure (like an actor or journalist) who posted
  • The number of likes, shares and comments a post receives from the world at large and from your friends in particular
  • How much you have interacted with this type of post in the past
  • Whether or not you and other people across Facebook are hiding or reporting a given post

TechCrunch reports on two other recent changes:

“Last Actor” looks at the 50 people you most recently interacted on Facebook such as viewing someone’s profile or photos, and liking their feed stories. Facebook then shows you more of them in your feed in the short-term. Say you browse through 100 photos of a girl you have a crush on, you’ll see more of her in your feed later that day. Note that this doesn’t mean anyone knows about your private Facebook browsing habits. This feature only affects what you see. The Last Actor algorithm change has been rolled out and is now impacting the web and mobile news feed.

“Chronological By Actor” is Facebook’s attempt to make real-time content more comprehensible. Say a friend is posting rapid updates about a football game. Showing them in ranked order regardless of their chronological order would be confusing, as you might see the game’s final score first, then a photo from half-time, then a touchdown in the third quarter, and then your friend’s excitement about the game starting. So Facebook will soon start to show these rapid real-time updates in chronological order so you see the first update first and the rest in order.

This largely confirms anecdotal evidence, but it is important that Facebook actually addresses how they deliver news to us.