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)

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)

Describes a study that collected statistics on the occurrence of terms used in searching an online catalog and investigated the correlation of the selection of terms with their occurrence in indexing. The discussion of the results includes implications for indexing theories. (19 references) (CLB)

Presents a theoretical rationale for employing a form of information retrieval algorithm that helps searchers better navigate through large document collections by continually revising probability estimates for document subsets. The algorithm avoids assumptions of index term independence and predicts relevance more accurately with increasing…

Describes three models for probabilistic indexing, all based on the Darmstadt automatic indexing approach, and presents experimental evaluation results for each. The discussion covers the improved retrieval effectiveness of probabilistic indexing over binary indexing, and suggestions for using this automatic indexing method with free text terms.…

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…

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…

This paper reviews the progress made so far in the development and use of expert systems for library and information services in the areas of online information retrieval, including gateway software and intelligent front-ends; cataloging, including bibliographic utilities and machine-aided cataloging; abstracting; reference work; and indexing and…

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)

Looks at some of the problems of finding digital geographic data in the electronic information infrastructure. Discusses the literature describing trends in organizing information resources in an electronic environment, including spatial information cataloging systems; the paper-based system from which they arose; and new Internet finding tools.…