Lexical Query Paraphrasing for Document Retrieval

We describe a mechanism for the generation of lexical paraphrases of queries posed to an Internet resource. These paraphrases are generated using WordNet and part-of-speech information to propose synonyms for the content words in the queries. Statistical information, obtained from a corpus, is then used to rank the paraphrases. We evaluated our mechanism using 404 queries whose answers reside in the LA Times subset of the TREC-9 corpus. Only 35% of the paraphrases were deemed corrected by human assessors. Nonetheless, there was a 14% improvement in performance when the paraphrases were used for document retrieval.