@techreport{oai:ipsj.ixsq.nii.ac.jp:00048128,
 author = {Tetsuya, SAKAI and Yoshimi, SAITO and Tomoharu, KOKUBU and Makoto, KOYAMA and Toshihiko, MANABE and Tetsuya, Sakai and Yoshimi, Saito and Tomoharu, Kokubu and Makoto, Koyama and Toshihiko, Manabe},
 issue = {93(2004-NL-163)},
 month = {Sep},
 note = {This paper explores the use of Question Abstraction  i.e.  Named Entity Recognition for questions input by the user  for reranking retrieved documents to enhance retrieval precision for Japanese Question Answering (QA). Question Abstraction may help improve precision because (a) As named entities are often phrases  it may have effects that are similar to phrasal or proximity search; (b) As named entity recognition is context-sensitive  the named entity tags may help disambiguate ambiguous terms and phrases. Our experiments using several Japanese ``exact answer'' QA test collections show that this approach significantly improves IR precision  but that this improvement is not necessarily carried over to the overall QA performance. Additionally  we conduct preliminary experiments on the use of Question Abstraction for Pseudo-Relevance Feedback using Japanese {?em IR} test collections  and find positive (though not statistically significant) effects. Thus the Question Abstraction approach probably deserves further investigations., This paper explores the use of Question Abstraction, i.e., Named Entity Recognition for questions input by the user, for reranking retrieved documents to enhance retrieval precision for Japanese Question Answering (QA). Question Abstraction may help improve precision because (a) As named entities are often phrases, it may have effects that are similar to phrasal or proximity search; (b) As named entity recognition is context-sensitive, the named entity tags may help disambiguate ambiguous terms and phrases. Our experiments using several Japanese ``exact answer'' QA test collections show that this approach significantly improves IR precision, but that this improvement is not necessarily carried over to the overall QA performance. Additionally, we conduct preliminary experiments on the use of Question Abstraction for Pseudo-Relevance Feedback using Japanese {\em IR} test collections, and find positive (though not statistically significant) effects. Thus the Question Abstraction approach probably deserves further investigations.},
 title = {High - Precision Search via Question Abstraction for Japanese Question Answering},
 year = {2004}
}