How Does Netflix Predict What You'll Like?
An August 7th, 2013 post to Wired discusses "The Science Behind the Netflix Algorithms."
In the article by Tom Vanderbilt, Carlos Gomez-Uribe, Netflix's VP of product innovation and personalization algorithms and Xavier Amatriain, Netflix's engineering director, discuss what data Netflix tracks and how it is used:
"Amatriain: We know what you played, searched for, or rated, as well as the time, date, and device. We even track user interactions such as browsing or scrolling behavior. All that data is fed into several algorithms, each optimized for a different purpose. In a broad sense, most of our algorithms are based on the assumption that similar viewing patterns represent similar user tastes. We can use the behavior of similar users to infer your preferences... We have been working for some time on introducing context into recommendations. We have data that suggests there is different viewing behavior depending on the day of the week, the time of day, the device, and sometimes even the location. But implementing contextual recommendations has practical challenges that we are currently working on. We hope to be using it in the near future."