The research on query expansion for Chinese question answering system

Abstract

In document retrieval, expanding query with words that are semantically related or frequently co-occur can get good performance. In Chinese question answering system, in order to improve answer-document retrieval precision, query expansion is also necessary. Aiming at the specialty of Chinese question answering system, a method of query expansion based on related words for specific question types and synonym in HowNet is proposed. A computing method of similarity between questions and documents based on minimal matching span is presented. This method is based on vector space model, and also fully considers the position information of query words and query expansion words in the documents. Finally, the experiment results show that the effect of expanding query makes better than unexpanded one. © Springer-Verlag Berlin Heidelberg 2005.