- Yangbo Zhu, Le Zhao, Jamie Callan. 2007. Structured Queries for Legal Documents Search. Abstract: This paper reports the experiments of using Indri for the main and routing (relevance feedback) tasks in the TREC 2007 Legal Track. For the main task, we analyze ranking algorithms using different fields, boolean constraints, phrase and synonym operators. Evaluation results show that structured queries outperform bag-of-words ones. For the routing task, we train a linear SVM classifier for each topic. Terms with the largest weights are selected to form new queries. Both keywords and simple structured features (term.field) have been investigated. Named-Entity tags, LingPipe sentence breaker and metadata fields of the original documents have been used to generate the field information. Results show that structured features and weighted queries improves retrieval, but only marginally. We also show which structures are more useful. It turns out metadata fields are not as important as we thought.
