Validation: A Critical First Step in the Evaluation of Systems for Legal Corpus Determination

The continued growth of very large data environments, both proprietary and Web-based, increases the importance of effective and ecient legal corpus selection and searching. Current “database selection” research focuses largely on completely autonomous and automatic selection, searching, and results merging in distributed environments. This fully automatic approach has significant deficiencies, including reliance upon thresholds below which data sets with relevant documents are not searched (compromised recall). It also merges result sets, often from disparate data sources, some that users may have discarded before their source selection task completed (diluted precision). We examine the impact that user interaction can have on the process of legal corpus selection. After analyzing thousands of real user queries, we show that precision can be significantly increased when queries are categorized by the users themselves, then interpreted and treated accurately by the system. As a precursor to evaluation, in this workshop, we present three behind-thescenes system validation exercises to assist us in determining whether certain system design decisions are justified in the context of our long-term goals of providing a corpus selection tool to legal practitioners. We ultimately show that by avoiding a one-size-fits-all approach that restricts the role users can play in information discovery, legal corpus selection eectiveness can be appreciably improved.