UIUC in HARD 2004--Passage Retrieval Using HMMs

UIUC participated in the HARD track in TREC 2004 and focused on the evaluation of a new method for identifying variable-length passages using HMMs. Most existing approaches to passage retrieval rely on pre-segmentation of documents, but the optimal boundaries of a relevant passage depends on both the query and the document. Our new method aims at determining or improving the boundaries of a relevant passage based on both the query and topical coherence in the document. In this paper, we describe the method and present analysis of our HARD 2004 evaluation results. The results show that the HMM method can improve the boundaries of pre-segmented passages in terms of overall passage retrieval accuracy and recall, but at the price of precision sometimes. However, due to the non-optimality of the relevance feedback procedure and the poor ranking performance based on passage scoring, the best of our passage runs is still worse than a whole document baseline run. Further experiments and analy...

• Type: Conference
• Year: 2004
• Where: TREC
• Authors: Jing Jiang, ChengXiang Zhai
• Keywords: Passage Retrieval, Passage Scoring, Relevant Passage, TREC 2004, TREC 2008