Abstract：Question-Answering is a hot research field in Natural Language Processing ,which includes many kinds of NLP technology. This paper introduces the current research status and the methods that are often used in Question-Answering. In general ,a Question-Answering system is made up of three parts : Question Analysis ,Information Retrieval and Answer Extraction. This paper describes the main functions of these three parts and the common approach used in these parts in detail. At last ,this paper introduces the evaluation of Question-Answering system.
[1] Ittycheriah ,M. Franz ,W-J Zhu ,A. Ratnaparkhi. IBM's Statistical Question Answering System. Proceedings of the night Text Retrieval Conference (TREC-9) [2] D. Elworthy.Question Answering Using a Large NLP System. Proceedings of the night Text Retrieval Conference (TREC-9) [3] L.Wu ,X-j Huang ,Y. Guo ,B.Liu ,Y. Zhang. FDU at TREC-9 :CLIR ,Filtering and QA Tasks. Proceedings of the night Text Retrieval Conference (TREC-9) [4] R. J. Cooper ,S.M. Rüger.A Simple Question Answering System. Proceedings of the night Text Retrieval Conference (TREC-9) [5] C. L. A. Clarke ,G. V. Cormack ,D. I. E. Kisman ,T. R. Lynam. Question Answering by Passage Selection. Proceedings of the night Text Retrieval Conference (TREC-9) [6] S-M Kim ,D-H Baek ,S-B Kim ,H-C Rim. Question Answering Considering Semantic Categories and Co-Occurrence Density. Proceedings of the night Text Retrieval Conference (TREC-9) [7] Richard J Cooper ,Stefan M Ruger.A simple Question Answering System. Proceedings of the night Text Retrieval Conference (TREC-9) [8] Ulf Hermjakob. Parsing and Question Classification for Question Answering. Proceeding of the workshop on Open-Domain Question Answering at ACL-2001 [9] Eugene Agichtein , Steve Lawrence ,Luis Gravano. Learning Search Engine Specific Query Transformations for Question Answering.ACM 2001 ,169 - 178 [10] Soo-Min Kim ,ae-Ho Baek ,Sang-Beom Kim ,Hae-Chang Rim Question Answering Considering Semantic Categories and Co-occurrence Density. Proceedings of the night Text Retrieval Conference (TREC-9) [11] Marius Pasca ,Sanda Harabagiu. High-Performance Question/Answering. 24th Annual International ACM SIGIR Conference on Research and Development in Information Retrieval (Sigir-01) . New Orleans ,LA. September 9 - 13 ,2001
2002, Vol. 16 
