A* Search Algorithm for Question Answering

In this paper, we propose a method to introduce an A search control into sentential matching mechanism for question-answering systems, in order to reduce the response time while the accuracy of the answer is preserved. The question answering is a new technology to retrieve not relevant documents but the answer(s) directly by combining several methodology including IR and IE. One of the essential processes is the sentential matching between the user’s query and each sentence in documents. In general, in order to obtain matching score precisely in higher resolution, we need some processes with higher computational costs. We therefore introduce an A search in which both the processing cost and the resolution of matching score are took into account simultaneously. According to the experiments in NTCIR3 QAC1 Task1, the system with the controled search is about 3.4–8.5 times faster than the system with no control.