A Dempster-Shafer Model for Query Expansion
Mingwen Wang, Jian‐Yun Nie · Journal of Jiangxi Normal University · 2005
AbstrcatQuery expansion is an effective way to extend the coverage of retrieval to the related documents. Various approaches have been proposed and many of them are simply adding expansion terms into the original query terms. In our early work we have showed that these simplistic expansion method can bias the focus of the original query, because the expanded terms add additional emphasis to the original term. Instead of adding expansion terms into the vector, we propose to combine them with the original terms by means of a logical OR operator. In this paper, we propose a query expansion computing model within the Dempster-Shafer Theory of Evidence.In the model, the original query terms are considered as primary evidences and the expansion terms are considered as auxiliary evidences to the original terms, and improve the Dempster-Shafer rule for query expansion.Experiments using the TREC collection show that our expansion method is more appropriate than the simple addition approach.