The implications of some major linguistic and semiotic concepts for the machine manipulation of natural language text are examined. It is proposed that the study of meaning should contribute to the development of sophisticated algorithms for machine indexing. (Author)

Reviews models currently used to describe the retrieval process and questions whether extensions of traditional approaches can provide mechanisms for expert retrieval systems. An alternative view in which retrieval is based on concept space is presented. A logic framework is used to define a semantic model for using knowledge contained in concept…

Discussion of the failure of individual keywords to identify conceptual content of documents in retrieval systems highlights Metric Similarity Modeling, a method for creating vector space representation of documents based on modeling target interdocument similarity values. Semantic relatedness, latent semantic indexing, an indexing and retrieval…

Describes exploratory experiments in evaluating and improving a thesaurus through studying its effect on retrieval. A formula was developed to measure the conceptual distance between queries and documents encoded as sets of thesaurus terms. Comparison to the performance of people judging conceptual distance shows that the formula accurately…

Describes the logical construction of several Russian hypertext systems, and discusses the navigational algorithms used, nodes selected, and coherence demanded. Several illustrative graphs are included, and an overview of the development of linking structures producing logical-semantic models is given. (20 references) (EA)

Presents an algorithm for use in natural language document retrieval systems which automatically determines if the conjunction "and" in a statement representing an information need should be translated into a Boolean "and" or "or." The results of an experiment that used the algorithm are reported, and further research is suggested. (CLB)