Facebook Feeds Rely on Data, Human Touch

Facebook is largely ruled by algorithms. But ultimately people must make judgments about what to show its 1.6 billion users, and how. That mutual dependence on software and people came into view this week following allegations that Facebook workers manipulated the “trending topics” feature by suppressing conservative viewpoints.

To decide what to show on its main news feed, Facebook relies on an algorithm, or computer program, that combs through roughly 100,000 signals and creates a “relevancy score” for each post for a specific user, Facebook says. An algorithm also governs what users see as trending topics. No two users see the same news feed or trending items. Facebook has become an important source of news for many users, who spend an average of 50 minutes a day on the social network, according to the company. Current and former employees say the algorithm is based on years of research observing how users interact with the network, and continual testing. But science goes only so far, and intuition plays a role as well, those current and former employees say.