Describes a hierarchical text database model and defines an algebra based on concordance lists. The algebra is presented as a theoretical model to define both a conceptual schema for the database and search protocols for database implementation. Several retrieval examples are included. (19 references) (MES)

Discusses the probabilistic nature of information retrieval, and describes a front end system designed to permit searchers to attach probabilistically interpreted weights to query terms, which could be adapted for conventional information retrieval systems without requiring radical changes in current indexing procedures. (37 references) (CLB)

Provides an overview of methods for improving the effectiveness of Boolean retrieval systems, including document clustering, relevance feedback, weighted term searching, ranked output, and fuzzy set theory. The discussion of experimental studies with the SMART and SIRE systems focuses on the implementation and results of these methods. (69…

Describes techniques used for information retrieval from free-text or document databases and presents a new approach based on signature files, or representations of documents, called the Map Array Signature (MAS) method. False drops are discussed, and results of experiments are compared to Robert's Superimposed Coding method. (20 references) (LRW)

Reports on the development of an NLP (natural language processing) component for processing the free-text comments on life insurance applications for evaluation by an underwriting expert system. A sublanguage grammar approach with strong reliance on semantic word classes is described. Highlights include lexical analysis, adjacency analysis, and…

Reports on the validity of the Multiple Poisson (nP) model of word distribution in full-text document collections. A practical algorithm for determining whether a certain word is distributed according to an nP distribution and the results of a test of this algorithm in three different document collections are described. (14 references) (KRN)

Describes the theoretical framework of a retrieval system that uses data structures called bitmaps to improve search algorithms for medium-sized systems. Information retrieval systems that contain the full text of the documents are discussed, and the use of inverted files such as concordances for small texts is explained. (24 references) (LRW)

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…

Describes a process of morpho-syntactic language analysis for information retrieval. Tree Structured Analytics (TSA) used for text representation is summarized; the matching process developed for such structures is outlined with an example appended; and experiments carried out to evaluate the effectiveness of TSA matching are discussed. (26…

Describes a model for the workload of a full text retrieval system and of a simulation model for a version of an existing system called Full/Text. The effectiveness of various data caching strategies using the 2 models are explored, and the impact of various parameters on the strategies are evaluated. (13 references) (LRW)

Discusses the problems of compressing a large textual database for storage on CD-ROM. A text-compression algorithm is presented, new algorithms for compression of indices are described, and the ARTFL (American and French Research on the Treasury of the French Language) database is used as an example. (14 references) (LRW)

Describes a study that was conducted to explore the potential of text analysis as a tool in full-text search and design improvement. A review of pertinent literature is included, and a trial analysis performed in the domain of family history literature is described. (Contains 49 references.) (LRW)

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…

Proposes a conceptual reference architecture for information retrieval systems and discusses functional capabilities of a hypertext environment, based on the proposed architecture, for interaction with large textual databases. Functions of the prototype system HYPERLINE are described, and an example of a user session is provided. (17 references)…

Describes a method based on Bayesian networks for searching hypertext systems. Discussion covers the use of Bayesian networks for structuring index terms and representing user information needs; use of link semantics based on constrained spreading activation to find starting points for browsing; and evaluation of a prototype system. (64…