Sourcerer is a system for automated location and retrieval of information available via World-Wide Web (WWW). It is a component of the National Library of Medicine (NLM) Unified Medical Language System (UMLS) Project, and builds upon the UMLS Metathesaurus, (which contains over 279,000 terms corresponding to over 152,000 distinct concepts, and unifies 25 separate defined vocabularies), and the UMLS semantic network (which tags thesaurus terms by semantic type, and lays out possible relationships between semantic types).
A forms-based entry tool, Apprentice, allows an information provider to remotely create a structured description of an information source. A human cataloger then adds index information using the NLM MeSH vocabulary as well as the UMLS semantic network, and adds the description to the Information Sources Map (ISM) database.
Sourcerer consists of a client and four different types of servers:
A user query is interactively refined with the assistance of the UMLS thesaurus server, which also maps the query terms into high-level concepts from the UMLS semantic network. These high-level concepts are used to retrieve a list of potentially useful information sources from the database on the ISM server, returned in the form of URNs. URNs are then resolved to URLs by a whois++ server. The user can then screen the proposed sources or connect to them automatically. In several instances, the original user query is passed along to the TIS using TIS-specific syntax.