UB at TREC Genomics 2006: Using Passage Retrieval and Pre-Retrieval Query Expansion for Genomics IR

This paper presents the results of the University at Buffalo (UB) in TREC genomics. For this task we used the SMART retrieval system and a pre retrieval expansion method that uses the ABGene and MetaMap tools. We tried two different weighting schemes one using pivoted length normalization (Lnu.ltu) and another using augmented tf-idf (atn.ann). The results show that performance of pivoted length normalization is very close to the median system that participated in the Genomics track. The augmented tf-idf performs significantly above the median system showing an improvement of 21%. This seems to indicate that a simpler weighting scheme could work better for retrieval of relevant passages.