15. The method of claim 1 , wherein rescoring includes calculating a total score for the query.
15. The method of claim 1 , wherein rescoring includes calculating a total score for the query. 16. The method of claim 15 , wherein total score is given by 
 s item =q×sw item +(1 −q )× sp item where sw item is a word score and sp item is a phrase score, and q is a tunable parameter between 1 and 0.