9. The system of claim 8 , wherein determining the measure of specificity for the selected hypernym comprises: determining the probability distribution for co-occurrence of the terms in the set of queries that are hyponyms of the selected hypernym; determining the background probability distribution for the occurrence of the terms in the set of queries; calculating the measure of specificity for the selected hypernym, based on the comparing.
9. The system of claim 8 , wherein determining the measure of specificity for the selected hypernym comprises: determining the probability distribution for co-occurrence of the terms in the set of queries that are hyponyms of the selected hypernym; determining the background probability distribution for the occurrence of the terms in the set of queries; calculating the measure of specificity for the selected hypernym, based on the comparing. 10. The system of claim 9 , wherein calculating the measure of specificity for the selected hypernym uses a Kullback-Leibler (KL) divergence between the probability distribution for co-occurrence of the terms in the set of queries and the background probability distribution.