The compatibility score of individuals in a social network is computed based on the compatibility of interests expressed by these individuals. The compatibility score between any two interests is calculated as the log of the estimated probability that a member of the social network will express both interests as his or her interests divided by the product of: (i) the estimated probability that a member of the social network will express the first of the two interests as his or her interest and (ii) the estimated probability that a member of the social network will express the second of the two interests as his or her interest. The compatibility score between two individuals is calculated as the sum of the compatibility scores between each interest appearing in a set of interests expressed by the first of the two individuals and each interest appearing in a set of interests expressed by the second of the two individuals.