53. The system of claim 23 in which each vector represents a corresponding user in a community, and each feature of each vector represents a preference of the corresponding user towards an object in a set of objects.
53. The system of claim 23 in which each vector represents a corresponding user in a community, and each feature of each vector represents a preference of the corresponding user towards an object in a set of objects. 55. The system of claim 53 , in which the set of objects includes at least one of a set of musical works or a set of dramatic works.