Discussion of models for information retrieval focuses on an application of linear algebra to text clustering, namely, a metric for measuring cluster quality based on the theory that cluster quality is proportional to the number of terms that are disjoint across the clusters. Explains term-document matrices and clustering algorithms. (Author/LRW)

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 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)

The Hepatitis Knowledge Base (text of prototype information system) was used for modifying and testing "A Navigator of Natural Language Organized (Textual) Data" (ANNOD), a retrieval system which combines probabilistic, linguistic, and empirical means to rank individual paragraphs of full text for similarity to natural language queries…

Discussion of user queries in information retrieval highlights the experimental evaluation of an adaptive linear model that constructs improved query vectors from user preference judgments on a sample set of documents. The performance of this method is compared with that of standard relevance feedback techniques. (28 references) (LRW)

Presents a coordination level matching algorithm to be used in document retrieval systems that incorporate relevance feedback strategies. It is argued that this algorithm may eliminate the need for the frequent reevaluation of documents that is currently found in such systems, and conditions under which reranking is unnecessary are given.…

Discusses the results of modeling the performance of searching large text databases via various parallel hardware architectures and search algorithms. The performance under load and the cost of each configuration are compared, and a common search workload used in the modeling is described. (Contains 26 references.) (LRW)