Query expansion method using answer candidates and the effect of combining their results on Web question-answering

In order to improve the accuracy of Web question-answering (QA) for factoid ques- tions, in this study, we examine the effect of a combination of several QA processes. We introduce a pseudo relevance feedback method in order to obtain different docu- ment sets. This feedback method is based on a query expansion technique using an- swer candidates obtained by the initial QA process. The expanded queries are used in the second QA process for retrieving other document sets. The final answer candi- dates of QA can be refined by combining the results of the second QA process. The experimental results show that the combi- nation of QA results obtained by using ex- panded queries improves the accuracy of answer candidates.