Paper: Corpus-based Question Answering for why-Questions

ACL ID I08-1055
Title Corpus-based Question Answering for why-Questions
Venue International Joint Conference on Natural Language Processing
Session Main Conference
Year 2008

This paper proposes a corpus-based ap- proach for answering why-questions. Con- ventional systems use hand-crafted patterns to extract and evaluate answer candidates. However, such hand-crafted patterns are likelyto have lowcoverage of causal expres- sions, and it is also difficult to assign suit- able weights to the patterns by hand. In our approach, causal expressions are automati- cally collected from corpora tagged with se- mantic relations. From the collected expres- sions, features are created to train an an- swer candidate ranker that maximizes the QA performance with regards to the corpus of why-questions and answers. NAZEQA, a Japanese why-QA system based on our ap- proach, clearly outperforms a baseline that uses hand-crafted patterns with a Mean Re- ciprocal Rank (top-5) of 0.30...