Research On Question Classification And Keyword Extension Of Chinese QA System

There are some differences between QA system and retrieval system. QA system firstly analyses questions according to the input question, and then finds the documents related to the question using retrieval system. Finally parses the documents and extracts the answers of the question input by the user. QA system contains four main procedures:Question Classification, Keyword Extension, Information Retrieval and Answer Extraction.The key technologies of QA System are firstly introduced in this paper, the methods of classification are compared, at the same time the key words expansion and answer extraction are introduced. And then classification algorithms and keyword expansion algorithm are mainly researched, the classification algorithm based on the combination of rule-based classification algorithm and statistical algorithms improves the accuracy of question classification, the final experiment compared the rule-based classification algorithm, based on Statistical classification algorithm and the algorithm of the combination of rule-based and statistical algorithms, experimental results show that the combination of the two classification algorithms improves the accuracy of classification problems; the combination of synonym expansion and semantic expansion of keyword expansion algorithm improves the keyword expansion effectiveness, the final experimental results show that the extension method is effective.