1. A computer-implemented method comprising: determining, by a computing system, a degree of separation between a user and a connection within a social network of the user, the connection associated with an interaction from which at least one topic is determined; determining, by the computing system, a value of affinity between the user and the connection; determining, by the computing system, a weight reflecting a value of interest similarity between the user and the connection; calculating, by the computing system, a term based on the degree of separation, the value of affinity, and the weight reflecting a value of interest similarity; and combining, by the computing system, terms associated with the at least one topic to generate a composite score associated with the at least one topic to determine whether to present the at least one topic to the user.