To facilitate legal research, companies, such as Thomson West provide subscription-based online information-retrieval systems. Seeking to improve these and/or related systems, the present inventors devised, among other things, an exemplary legal research system that performs a conventional search to identify a set of starter documents and then leverages the metadata associated with these starter documents to identify another larger set of relevant documents. Documents in this alternate set are then scored using, for example, a learning machine and feature vectors that account for metadata relationships between the starter documents and alternate documents.