The objectives of this paper are to describe the effect of using weighted index terms in a document retrieval system, and to evaluate retrieval performance when queries are expanded by terms occurring in clusters with the query terms. Three data collections, each indexed by several methods, two of which were studied and reported on in previous…

WISE-ONE is a bibliographic information retrieval system which is designed to perform keyword searches of such data-bases as the ERIC RESUMAST and the ERIC CIJEMAST. Produced as a result of the search are the ERIC citation numbers, titles, authors, and, in the case of the journal file, the journal citation. Because WISE-ONE allows for nesting of…

The study compares the retrieval effectiveness of two alternative input and search systems in terms of such measures as recall, fallout, precision, and total retrieval. One system uses manually indexed document files searched by controlled vocabulary, while the other employs fulltext input using natural language searching. Both systems are applied…

The purpose of the study was to determine how many questions judged relevant to an article are also judged relevant using different length representations of the article, and how this proportion changes as the length of the representation changes. Several persons made relevance judgments for each of a set of articles to each of a set of questions.…

The purpose of the investigation was to determine how effectively biomedical practitioners, with a minimum of introduction to the system, can conduct on-line searches to satisfy their own information needs. The searches were conducted on the Abridged Index Medicus data base as implemented on the on-line ELHILL system (AIM-TWX). ELHILL is the ORBIT…

Reports an investigation conducted to improve the performance of SDI profiles in a large, complex data base that contains over a million references to scientific and technical literature, and uses full text indexing for retrieval. (Author/MBR)

Introduces the concept of cover coefficient to indexing theory and discusses a way of computing term discrimination values by using the cover coefficient concept, index-term selection, and weight modification. This method is compared to an approach that uses similarity coefficients. (Author/EM)

Describes GRANT, an expert system for finding sources of funding given research proposals. The architecture of GRANT and the implementation of constrained spreading activation (a modified search algorithm based on semantic memory) are described, and recall and precision rates are analyzed. (Author/LRW)

Discusses expert systems and their value as components of information retrieval systems related to semantic inference, and describes IOTA, a model of an intelligent information retrieval system which emphasizes natural language query processing. Experimental results are discussed and current and future developments are highlighted. (Author/LRW)

A Bayesian argument is used to suggest modifications to the Robertson and Jones relevance weighting formula to accommodate the addition to the query of terms taken from the relevant documents identified during the search. (Author)

Reviews the subjective probability estimation literature of six schools of human judgement and decision making: decision theory, behavioral decision theory, psychological decision theory, social judgement theory, information integration theory, and attribution theory. Implications for probabilistic information retrieval are discussed, including…

Describes an expected precision (EP) measure designed to predict document retrieval performance. Highlights include decision theoretic models; precision and recall as measures of system performance; EP graphs; relevance feedback; and computing the retrieval status value of a document for two models, the Binary Independent Model and the Two Poisson…

Identifies characteristics of the experienced online searcher and discusses the results of three searches carried out by a variety of searchers in widely differing subject fields--presence of arsenic in coal, problems of working alone in laboratory or work area, and spectral sensitivity of the insect eye. (8 references) (EJS)

Examines the changing role of controlled vocabulary in the postcoordinate online search, particularly its current role in the formulation of online search strategies. Effects of controlled vocabulary searching on precision and recall and examples of concept "hedges" from the "Thesaurus of ERIC Descriptors" are discussed. Nine…

This paper reports on a transaction log analysis of 51,473 queries from 18,113 users of Excite, a major World Wide Web search engine. Approximately 2,500 of these queries were from the use of relevance feedback. Given the high level of research activity and historical success of relevance feedback in assisting users in locating relevant…