AND 100 DOCUMENTS RETRIEVED VIA THE GOOGLE APIFOR EACH QUESTION, A...

50, and 100 documents retrieved via the Google APIfor each question, and extracted the most frequentG.A. Miller, R. Beckwith, C. Fellbaum, D. Gross,fifty n-grams (up to trigrams). The goal was to de-and K. Miller. 1990. Five papers on wordnet. In-termine the quality of query expansion as measuredternational Journal of Lexicography.by the density of correct answers already presentD. Moldovan, D. Clark, S. Harabagiu, and S. Maio-in the expansion terms. Even without filtering n-rano. 2003. Cogex: A logic prover for questiongrams matching the expected answer type, simpleanswering. ACL.PRF produces the correct answer in the top n-gramsE. Nyberg, T. Mitamura, J. Callan, J. Carbonell,for more than half the questions. The best correctR. Frederking, K. Collins-Thompson, L. Hiyaku-answer density is achieved using PRF with only 20moto, Y. Huang, C. Huttenhower, S. Judy, J. Ko,web documents.A. Kupsc, L.V. Lita, V. Pedro, D. Svoboda, andB. Vand Durme. 2003. A multi strategy approach