Jamie's research group studies full-text information retrieval, including retrieval of structured (XML) documents, full-text search in peer-to-peer networks, text retrieval for reading and ESL/ELL tutors, and text mining in large public comment repositories. His group and Bruce Croft's group at UMass, Amherst develop and distribute Lemur , an open-source system for text retrieval research. Jamie's earlier IR research studied architectures for large-scale information retrieval and adaptive filtering systems, and first generation Web-search systems.