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)

Presents a methodology for extending string indexing from index display production to the provision of descriptor phrases for term proximity searching. Objectives of the extension are discussed, and an illustration of the use of an existing string indexing system for this purpose is given. (14 references) (CLB)

Discusses properties of multiple attribute tree (MAT) and inverted file structures; establishes suitability of MAT data structure for bibliographic files using worst-case performance measures; provides arguments to establish MAT average case superiority; and proposes an efficient adaptation of MAT data structure to exploit special features of MAT…

Provides overview of Ergonomics Abstracts Retrieval System (EARS), an online bibliographic search and retrieval system in the area of human factors engineering. Other online systems are described, the design of EARS based on inverted file organization is explained, and system expansions including a thesaurus are discussed. (Author/LRW)

Explores the fundamentals of browsing behavior as a basis for the creation of an intelligent computer system to assist in online information retrieval. A prototype system is described, and the results of initial tests are reported. (5 references) (Author/CLB)

Presents an overview of the IR-NLI II system, an expert interface that allows users to access online information retrieval systems and that encompasses user modeling capabilities. Highlights include the design of the system, the structure and content of stereotypes that represent typical classes of users, and construction of user models.…

This discussion of the structure of online databases and the structure of related subject disciplines focuses on terms used in a book about tropical diseases and terms used in the MEDLINE database for articles on these diseases. Matrices used are explained and Medical Subject Heading (MeSh) terms are examined. (16 references) (LRW)

Describes study that compared and judged the quality of subject indexing in online bibliographic databases. Documents from medical behavioral science literature are used with terms drawn from MEDLINE, PsychINFO, BIOSIS, and Excerpta Medica. Comparative statistics are presented on how each database links related documents and discriminates among…

This review of abstracting policies used by database producers focuses on the degree to which these policies incorporate criteria vital for acceptability of abstracts for free-text searching. Each topic in abstracting policy (abstract type, length, content, and language) is examined to consider its effect on retrieval. (MBR)

Discusses indeterminancy of selection of terms by indexers and by inquirers as major factors influencing subject access to documents in document retrieval systems. Five types of interactions between these two indeterminancies are discussed, and a change in traditional method of subject searching is suggested to reduce effect of inter-indexer…

Reports algorithm for calculation of term discrimination values that is sufficiently fast in operation to permit use of exact values. Evidence is presented to show that relationship between term discrimination and term frequency is crucially dependent upon type of inter-document similarity measure used for calculation of discrimination values. (13…

Zipfian laws for frequency distributions of word pairs and longer phrases are derived from text sample analysis. From crossing of Zipfian curves, it is deduced that number of multi-word phrases that occur frequently in text is surprisingly small, of same order of magnitude as number of individual word-types. (8 references) (EJS)

The U.S. Department of Energy (DOE) software research and development project described explores information seeking behavior of end-user energy experts and develops software offering tutorials on front-end use of DOE/RECON databases and active help in performing online searches. Software development is described and results of prototype testing…

Describes experiment designed to assess information value for individual searchers in realistic search environment. Included in data analysis are comparison of two alternative retrieval methods, evaluation of how well humans are able to estimate document relevance, and investigation of value function components (features and coefficients) and…

Presents results of five experiments on human information-seeking behavior in different online information-seeking environments which studied search strategies and assessed information value in realistic search environments. A conceptual model of how humans value information is presented. Empirical and modeling results are considered for…