Describes large scale experiments to test the value of index term weighting based on relevance information, and presents results showing that weighting leads to remarkable improvements in retrieval performance. (Author/CWM)

Describes a model of an information retrieval system based on a thesaurus with weights. Appropriate terms are defined, and inclusiveness and two other fundamental properties of the system are presented. (CWM)

To investigate the relationship between the retrieval mechanism and the level of question elaboration, this study divided 100 questions from the cystic fibrosis database into five conceptual categories based on their semantic representations. Two retrieval methods were chosen to investigate potential differences in outcomes across conceptual…

This report on the Getty Online Searching Project, which studied the end-user searching behavior of 27 humanities scholars over a 2-year period, focuses on previous familiarity with retrieved documents. Topics include document familiarity and relevance; document familiarity and information retrieval; measuring retrieval success; and document…

Describes a study that computed the low performance standards for queries in 17 test collections. Predicted by the hypergeometric distribution, the standards represent the highest level of retrieval effectiveness attributable to chance. Operational levels of performance for vector-space and other retrieval models were compared to the standards.…

Explores the use of linear models and a combination of neural networks and linear classifiers to create a hybrid hierarchical mixture of experts (HME) model. Results confirm that using the hierarchical structure of the classification vocabulary improves categorization performance. (AEF)

Reports on an exploratory study of the criteria searchers use when judging the relevance of recorded speech from radio programs and the attributes of a recording on which those judgments are based. Criteria used as a basis for selection were found to be similar to those observed in relevance studies with printed materials, but attributes used as a…

Provides an overview of some of the main ideas in the philosophy of language that have relevance to the issues of information retrieval, focusing on the description of the intellectual content. Highlights include retrieval problems; recall and precision; words and meanings; context; externalism and the philosophy of language; and scaffolding and…

Reports on a study that tested the efficacy of an information retrieval system output summary and visualization scheme for undergraduates taking a Vietnam War history course who were in Kuhlthau's Stage 3 of researching a history essay. No significant difference was found between the mean marks for students in the visualization scheme group or the…

Discusses term weighting formulae and their use for selecting new terms to enhance a search statement and for weighting the terms for retrieval purposes once selected. The Swets model of information retrieval system performance is described, an approach to term selection is presented, and future research is suggested. (five references) (LRW)

Discusses the interdependencies between parameter estimation and properties of probabilistic models, such as dependency assumptions, binary vs. nonbinary features, and estimation sample selection. An optimum estimation for binary features applicable to information retrieval is defined, a method for computing this estimation using empirical data is…

Discusses the feasibility of building intelligent rule- or weight-based algorithms into general-purpose software for interactive thesaurus navigation. Previous research is surveyed; practical investigations in thesaurus navigation and query enhancement are described; and implications for automatic or intelligent thesaurus navigation are…

Reviews past research on user-satisfaction and relevance information systems. Describes an experiment that compares user-satisfaction with retrieved items and the retrieval process with the relevance of the items in resolving user information needs. Results indicate a connection exists between relevance and user-satisfaction with the retrieved…

Examines the transition from traditional single database retrieval to the emerging networked resources retrieval, and presents research and experimental solutions developed at the University of California, Berkeley. Highlights include recall and relevance, network navigation, vocabulary, and extending retrieval records. (LRW)

Research designed to identify the best evaluation measure(s) for interactive information retrieval (IR) performance studied 20 measures in a natural IR environment with 40 real end users. These users found overall search value to be the most important factor and recall was more important than precision. Additional evaluation criteria are suggested…