The algorithm that originally determined the order of content in Facebook’s News Feed was EdgeRank.
EdgeRank evaluated each potential News Feed item using three core ideas: a user’s affinity to the creator, the type and amount of interaction an item attracted, and time decay. A commonly cited simplified formula is affinity × weight × decay. The system helped decide which posts were more likely to appear near the top of a user’s feed.
EdgeRank was developed and implemented by Facebook engineer Serkan Piantino. Facebook moved away from the original system around 2011, replacing it with increasingly complex machine-learning models. By 2013, Facebook said its ranking system considered more than 100,000 factors.
A common mix-up is PageRank, Google’s web-page ranking algorithm, or Timeline, Facebook’s profile feature. EdgeRank is the historical name associated specifically with News Feed ranking, even though Facebook no longer uses the original formula.