1. A method using a computer system for automated retrieval of numeric information from a set of electronic source documents, comprising: receiving an electronic query comprising one or more keywords from a remote user computer system via a telecommunications network; accessing a computer-searchable index comprising a plurality of searchable index entries, at least a plurality of the entries each including a representation of an associated unit of measure extracted from the electronic source documents; automatically determining a query unit, at least partly by identifying one or more related occurrences within the electronic source documents of said one or more keywords and one or more of said units of measure; and assessing the relevance of one or more of the index entries to the electronic query, at least partly based on a comparison of the query unit and the unit associated with one or more of said index entries.