Chapter

Intelligent Information Processing III

Volume 228 of the series IFIP International Federation for Information Processing pp 123-133

QA System Metis Based on Web Searching and Semantic Graph Matching

  • Dongli HanAffiliated withDepartment of Computer Science and System Analysis, NINON University
  • , Yuhei KatoAffiliated withDepartment of Integrated Information Technology, Aoyama Gakuin University
  • , Kazuaki TakeharaAffiliated withDepartment of Integrated Information Technology, Aoyama Gakuin University
  • , Tetsuya YamamotoAffiliated withDepartment of Integrated Information Technology, Aoyama Gakuin University
  • , Kazunori SugimuraAffiliated withDepartment of Integrated Information Technology, Aoyama Gakuin University
  • , Minoru HaradaAffiliated withDepartment of Integrated Information Technology, Aoyama Gakuin University

Abstract

We have developed a question-answering system Metis with natural-language interface. Metis generates the answer to a question by comparing the semantic graph of the question sentence with sentences discovered on the Internet as knowledge source. Specifically, we first get a set of semantic frames for the question sentence, as the output from a semantic analysis system, SAGE, Then we extract several keywords from all semantic frames using SVM. After that we search the Web to find knowledge sentences based on the keywords and input each knowledge sentence into SAGE in order to get its semantic graphs similarly. Finally, the similarities between the semantic graph of the question sentence and that of each knowledge sentence are calculated to determine the most reliable knowledge sentence, in which a constituent is chosen as the answer to the question. An experiment to examine the effectiveness of our method showed that 65% of the questions for which suitable knowledge sentences had been found were replied correctly.

Key words

Natural Language Processing Question Answering System Semantic Analysis EDR-Dictionary