3.1 Sparsity:Applications and Development Movies The Netflix prize: ? ? ? ? ? ? ? ? ? ? ? ? ? ? Users ? ? ? ? ? ? ? ? ? ? ? ? About a million users and ? ? ? ? ? ? ? ? ? ? 25000 movies ? Known rankings are sparsely distributed Predict unknown ratings3.1 Sparsity: Applications and Development The Netflix prize: About a million users and 25000 movies Known rankings are sparsely distributed Predict unknown ratings