摘要: Long queries frequently contain many extraneous terms that hinder retrieval of relevant documents. We present techniques to reduce long more effective shorter ones lack those terms. Our work is motivated by the observation perfectly reducing TREC description can lead an average improvement 30% in mean precision. approach involves transforming reduction problem into a learning rank all sub-sets original query (sub-queries) based on their predicted quality, and selecting top sub-query. use various measures quality described literature as features represent sub-queries, train classifier. Replacing with top-ranked sub-query chosen ranker results statistically significant 8% our test sets. Analysis shows well-suited for moderately-performing queries, small set predictors are task ranking sub-queries.