1. A method for processing user profiles of a plurality of users in an electronic community, said method comprising: extracting, by a processor of a data processing system, noun phrases from activities of each user logged in an activity log server, each user having an existing user profile stored in a user profile and relationship database that is external to the activity log server; said processor updating the existing user profiles in the user profile and relationship database from the extracted noun phrases, a keyword being associated with each determined noun phrase and being within a semantic hierarchical tree, said updating based on a usage frequency of the extracted noun phrases and an importance value of the keywords; said processor executing a similarity based clustering algorithm to generate clusters of the updated user profiles, each cluster comprising a group of users of the users in the electronic community, each cluster representing a relationship between the users in each group; and said processor storing each cluster in the user profile and relationship database, wherein the similarity based clustering algorithm comprises a member importance function and a member similarity function, wherein the member importance function ascertains an importance value of keywords as a depth of said keywords in the semantic hierarchical tree, wherein the member similarity function ascertains a similarity distance between keywords as a path distance between said keywords in the semantic hierarchical tree, and wherein said executing the similarity based clustering algorithm comprises: using the member importance function and the member similarity function to ascertain the clusters.