5. The method of claim 4 , identifying the at least one contextual keyword from the structure that has a co-occurrence score with the received query greater than a predetermined co-occurrence threshold.
5. The method of claim 4 , identifying the at least one contextual keyword from the structure that has a co-occurrence score with the received query greater than a predetermined co-occurrence threshold. 6. The method of claim 5 , identifying the at least one contextual keyword from the structure that has a co-occurrence score with the received query within a predetermined range if lexical generality of the query is less than a predetermined generality threshold.