6. The method according to claim 5 , wherein estimating the relative generality and specificity of the first query and the candidate query further comprises: determining if the difference between the relative coverage of the first query relative to the candidate query and the relative coverage of the candidate query relative to the first query is greater than a second threshold value; determining if the difference between the relative coverage of the candidate query relative to the first query and the relative coverage of the first query relative to the candidate query is greater than the second threshold value; and classifying the relationship between the first query and the candidate query as a parent relationship, a child relationship, or a sibling relationship according to determined differences, or lack thereof, in the relative coverage of the first query relative to the candidate query and the relative coverage of the candidate query relative to the first query.
8. The method according to claim 6 , wherein constructing the query hierarchy further comprises arranging the first query and the candidate queries based upon their derived relative classification.