A method and system for populating a concept database based on a plurality of multimedia data elements (MMDEs) and at least one user identifier, the concept database including a plurality of concept structures. The method includes clustering a plurality of signatures of the plurality of MMDEs into a cluster of signatures; reducing the number of signatures in the cluster to a create a signature reduced cluster (SRC); generating, based on the SRC and the plurality of concept structures, an index, wherein the index maps the plurality of MMDEs to a matching concept structure of the plurality of concept structures; associating the index with a user based on the at least one user identifier; and storing the index and the plurality of MMDEs in the concept database.