Probabilistic data fusion on a large document collection

Data fusion is the process of combining the output of a number of Information Retrieval (IR) algorithms into a single result set, to achieve greater retrieval performance. ProbFuse is a data fusion algorithm that uses the history of the underlying IR algorithms to estimate the probability that subsequent result sets include relevant documents in particular positions. It has been shown to out-perform CombMNZ, the standard data fusion algorithm against which to compare performance, in a number of previous experiments. This paper builds upon this previous work and applies probFuse to the much larger Web Track document collection from the 2004 Text REtreival Conference. The performance of probFuse is compared against that of CombMNZ using a number of evaluation measures and is shown to achieve substantial performance improvements.