University of Iowa at TREC 2008 Legal and Relevance Feedback Tracks

摘要

This is the second year that our research group has participated in the TREC Legal Track. Our ad hoc retrieval system has been modified to extract the additional Boolean query fields added to the 2008 topics, and to privilege documents found by the Boolean reference run when conducting our queries. We have also submitted runs that fuse the results from existing runs. For the relevance feedback task, our system uses ranking information of relevant and non-relevant documents from previously submitted runs to the TREC Legal Track to train a classifier. The classifier is applied to the remaining unjudged documents to create a new ranked list. This approach is applied to sets of input runs, including a hybrid run where a classifier trained on one set of runs is applied to the unjudged documents from another set of runs. Our index remains unchanged from our submission to TREC Legal in 2007, and new changes to our retrieval system are accomplished through the selection of topic fields for input and post-retrieval processing.