An operational system for subject switching between controlled vocabularies

• Published in: Information processing & management Vol. 29; no. 1; pp. 47 - 59
• Main Authors: Silvester, June P., Klingbiel, Paul H.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1993; Elsevier Science; Pergamon Press; Elsevier Science Ltd
• Subjects: Automatic Indexing; Case studies; Content analysis; Defense Technical Information Center; Defense Technical Information Center, USA; Exact sciences and technology; Federal Government; Government agencies; Indexing. Classification. Abstracting. Syntheses; Information and communication sciences; Information and document structure and analysis; Information centers; Information management; Information processing; Information processing and retrieval; Information science. Documentation; Knowledge based systems; NASA; National Aeronautics and Space Administration; Public Agencies; Sciences and techniques of general use; Subject Index Terms; Systems Development; Thesauri; United States > US; Concept; Productivity; System evaluation; Computer aided indexing; Information conversion; Knowledge base; Switching; Information language; Documentation data processing; Subject content; Indexer; Language processing; Applied linguistics; Controlled vocabulary; Profit; Natural language; Automatic analysis; Computer aid; Indexing
• ISSN: 0306-4573; 1873-5371
• DOI: 10.1016/0306-4573(93)90022-6

The NASA system of automatically converting sets of terms assigned by Department of Defense indexers to sets of NASA's authorized terms is described. This little-touted system, which has been operating successfully since 1983, matches concepts, rather than words. Subject Switching uses a translation table, known as the Lexical Dictionary, accessed by a program that determines which rules to follow in making the transition from DTIC's to NASA's authorized terms. The authors describe the four phases of development of Subject Switching, changes that have been made, evaluating the system, and benefits. Benefits to NASA include saving indexers' time, the addition of access points for documents indexed, the utilization of other government indexing, and a contribution towards the now-operational NASA, online, interactive, machine aided indexing.