Intro to Implicit Matrix Factorization: Classic ALS with Sketchfab Models | Ethan Rosenthal

Last post I described how I collected implicit feedback data from the website Sketchfab. I then claimed I would write about how to actually build a recommendation system with this data. Well, here we are! Let’s build. I think the best place to start when looking into implicit feedback recommenders is with the model outlined in the classic paper “Collaborative Filtering for Implicit Feedback Datasets” by Koren et.al. (warning: pdf link).