Describes a system developed at the National Aeronautics and Space Administration (NASA) that automatically converts index terms from the Defense Technical Information Center (DTIC) to NASA thesaurus terms. The NASA Lexical Dictionary (NLD) that generates thesaurus terms for indexing is explained, and the development of machine-aided indexing is…

Outlines an approach to the automatic construction of a knowledge base resulting in a system that is able in each phase of its construction to acquire domain knowledge from all new information that it is building, particularly index terms. Topics covered include production rules, the use of semantic networks, and user interfaces. (32 references)…

Describes the three subsystems of an information retrieval system (document descriptions, queries, and matching algorithms) and argues that the interdependency of these subsystems requires adaptation for the system to perform when any component changes. An algorithm for redescribing documents, in response to changes in queries and retrieval rules,…

Discusses the motivation for integrating information retrieval and database management systems, and proposes a probabilistic retrieval model in which records in a file may be composed of attributes (formatted data items) and descriptors (content indicators). The details and resolutions of difficulties involved in integrating such systems are…

Presents a relational logical model to support a sophisticated document retrieval system in which flexible forms of inferential and associative searching can be performed, and provides examples of ad hoc inquiries. Several problems of particular importance to document retrieval are discussed in terms of this model. (27 references) (Author/CLB)