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)

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…

Investigates the value of applying principles derived from simulated annealing to clustering tuples in database design, and compares this technique with a graph-collapsing clustering method. It is concluded that, while the new method does give superior results, the expense involved in algorithm run time is prohibitive. (24 references) (CLB)

Discusses ranking techniques for document retrieval and proposes an evaluation, or filtering, technique that reduces costs and memory usage by early recognition of which documents are likely to be highly ranked. Highlights include index design, ranked query evaluation, reducing the number of accumulators, inverted file structures, and experimental…

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)

Discusses the design of multiversion information retrieval systems and provides a theoretical justification for the necessity of creating such systems to perform an optimal search for the user's information needs. Topics discussed include comparing query formulations; feedback algorithms; an experiment with a test collection; and the mechanism of…

Describes animation algorithms for creating smooth functions of time- and space-varying phenomenon. The incidence of the disease mumps from 1968-88 in the United States is used to demonstrate the algorithms. Figures that illustrate the findings are included. (14 references) (KRN)

Describes the unique reliability problems of very large databases that necessitate specialized techniques for hardware problem management. The discussion covers the use of controlled partial redundancy to improve reliability, issues in operating systems and database management systems design, and the impact of disk technology on very large…