… There is a special sauce necessary to making big data work: surveys and the judgment of humans — two seemingly old-fashioned approaches that we will call small data. …
To get to these measures, Facebook has to take an old-fashioned approach: asking. Every day, hundreds of individuals load their news feed and answer questions about the stories they see there. Big data (likes, clicks, comments) is supplemented by small data (“Do you want to see this post in your News Feed?”) and contextualized (“Why?”). CONT.
Alex Peysakhovich (Facebook) & Seth Stephens-Davidowitz, New York Times