1. A computer-implemented method to resolve identity records received by an entity resolution system and referencing a common individual, the computer-implemented method comprising: resolving a received identity record against a set of known entities in the entity resolution system to identify a first entity to associate with the received identity record, the first entity representing a first individual; identifying one or more entities related to the first entity; determining a base relevance score to assign to the first entity based on relevance scores assigned to one or more identity records associated with the first entity; determining an association relevance score to assign to the first entity, based on a relevance score assigned to at least one related entity and a relationship strength between the entity and the at least one related entity; and responsive to a search request, determining a search relevance score of the first entity, based on at least one of the base relevance score and the association relevance score and by operation of one or more computer processors, wherein the search relevance score is output and represents a quantitative measure of relevance of the first individual to the search request.