Recall and precision devices in interactive bibliographic search and retrieval systems

Abstract

An index language usually incorporates various methods for improving recall and/or precision when searching. Recall devices tend to increase the size of retrieved document sets, while precision devices tend to reduce them. The most common recall and precision devices are described in general terms and their usage in several thesauri is examined. The thesauri looked at relate to databases available for searching in the ESA IRS online information system at one time or another and include the NASA Thesaurus; Thesaurus of Engineering and Scientific Terms; Thesaurus of Metallurgical Terms; Subject Headings used by the USAEC; Subject Headings for Engineering; INIS Thesaurus and the INSPEC Thesaurus. The extent to and the way in which the recall and precision devices are used in the ESA IRS online system for controlled and uncontrolled subject term searching are discussed.