Describes a model for a front end query processor to deal with incomplete information in a database. The effectiveness of the processor in restricting the number of objects to be processed in a query and in aiding the interpretation of a query is discussed. (26 references) (Author/CLB)

Reports on a project showing that relational data models, including unnormalized models that allow the nesting of relations, cannot fully capture the structural properties of lexical information. A feature-based model that allows for a full representation of some nesting and defines a factoring mechanism is described and demonstrated. (38…

Analyzes different kinds of reformulations used in information retrieval systems where full text databases are accessed through natural language queries. Tests of these reformulations on large full text databases managed by the Syntactic and Probabilistic Indexing and Retrieval of Information in Texts (SPIRIT) system are described, and an expert…

Presents a model for the a priori analysis of natural language queries which uses an algorithm to transform the query into a logical pattern that is used to determine the answerability of the query. The results of testing by a prototype system implemented in PROLOG are discussed. (20 references) (CLB)

Describes the hyperterm system REALIST (Retrieval Aids by Linguistics and Statistics) with emphasis on its semantic component, which generates term relations from free-text input. Experiments with various similarity measures are discussed, and the quality of the associated terms is evaluated using term recall and term precision measures. (22…