2007 Volume 24 Issue 3 Pages 3_20-3_28
There have been many studies on question-answering systems on the Web. Some of them try to find the answers to “Who”, “When” and “Where” type questions. However, there are few studies on practical systems which allow “Why” type questions. Because “Why” type questions need sentences for the answers and traditional and typical methods give the answers as a phrase or a word. Therfore we have proposed and implemented a prototype system “RE:Why” for extracting answers to a “Why” type question. RE:Why adopts new method which pays attention to the structual relations between sentences of a question and sentences of the answer on the Web. We have conducted experiments using twenty questions and have compared the performances between RE:Why and a traditional keyword search engine by measuring precisions and recalls.