Implicit data and collaborative filtering

1 · Erik Bernhardsson · Sept. 16, 2013, 4 a.m.
A lot of people these days know about collaborative filtering. It’s that Netflix Prize thing, right? People rate things 1-5 stars and then you have to predict missing ratings. While there’s no doubt that the Netflix Prize was successful, I think it created an illusion that all recommender systems care about explicit 1-5 ratings and RMSE as the objective. Some people even distrust me when I talk about the approach we take at Spotify. Misconception 1: Recommender systems are about predicting missi...