1. A method, in a natural language processing (NLP) system comprising a processor and a memory, the method comprising: receiving, by the NLP system, a plurality of communications associated with a communication system, over a predetermined time period, from a plurality of end user devices; identifying, by the NLP system, for each communication in the plurality of communications, a user submitting the communication to thereby generate a set of users comprising a plurality of users associated with the plurality of communications; retrieving, by the NLP system, a user model for each user in the set of users, wherein the user model specifies at least one attribute of a corresponding user; generating, by the NLP system, an aggregate user model that aggregates the at least one attribute of each user in the set of users together to generate an aggregate representation of the attributes of the plurality of users in the set of users; and performing, by the NLP system, a cognitive operation based on the aggregate user model.