I don't get the innovation in this paper - are they just running word2vec on groups of items? If so, Spotify has been doing this on playlists for years now: <a href="https://erikbern.com/2013/11/02/model-benchmarks/" rel="nofollow">https://erikbern.com/2013/11/02/model-benchmarks/</a><p>Also, I know the paper isn't claiming state-of-the-art, but their SVD results are horrendous. Standard CF would create much better artist-artist pairings with even a medium sized dataset.<p>As an aside, I've run some quantitative and qualitative tests and have found the best recommendations come from a combination of user-item and item-item. I co-gave a talk at the NYC machine learning meetup recently (<a href="https://docs.google.com/presentation/d/1S5Cizi9LFQ7l0bMYtY7gASvOPqxNsQk0-NuP5KWAl-4/pub?start=false&loop=false&delayms=3000&slide=id.p4" rel="nofollow">https://docs.google.com/presentation/d/1S5Cizi9LFQ7l0bMYtY7g...</a>) that shows how this can work, starting at slide 20. The idea is to create a candidate list of matches using item-item, and then reorder using item-user. I've found this creates "sensible" suggestions using item-item, but truly personalizes when re-ordering. You can remove obvious recommendations by removing popular matches or matches the user has already interacted with (I consider this a business decision rather than something inherent in the algorithm).