1. A computer-implemented method comprising: determining, by a computing system, at least one topic for potential presentation to a user based on an interaction of a connection of the user on a social networking system; determining, by the computing system, a degree of separation between the user and the connection within the social networking system; 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.
1. A computer-implemented method comprising: determining, by a computing system, at least one topic for potential presentation to a user based on an interaction of a connection of the user on a social networking system; determining, by the computing system, a degree of separation between the user and the connection within the social networking system; 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. 8. The computer-implemented method of claim 1 , further comprising: sorting composite scores associated with topics; and ranking the topics according to the composite scores to identify a cluster of the topics.