The purpose of this communication is to suggest that in the situation where documents are retrieved independently the desired parameters may be estimated more accurately by sampling and averaging techniques over homogeneous subparts of the data base. (4 references) (Author)

Entropies of surrogates such as citations, abstracts, first paragraphs, last paragraphs, and first and last paragraphs are measures of how well each class of surrogates predicts relevancy of documents. They are measures of meaningful information in the text of surrogates. Such measures of information are important to information system designers.…

The use of Boolean not" logic in selective dissemination of information produced greater user satisfaction, less nonpertinent information, and no apparent decrease in the number of pertinent retrievals. (9 references) (SJ)

In experimental searches of "Basic Journal Abstracts" using the subject terms from 104 selective dissemination of information profiles, retrieval was found to be significantly worse if only titles were searched rather than the full title and abstract. (PF)

A threshold rule is analyzed and compared to the Neyman-Pearson procedure, indicating that the threshold rule provides a necessary but not sufficient measure of the minimal performance of a retrieval system, whereas Neyman-Pearson yields a better apriori decision for retrieval. (Author/MBR)

Discussion of probabilistic information retrieval (IR) systems challenges the probability ranking principle in IR from the perspective of (1) signal detection-decision theory and (2) utility theory. Calibration, certainty, and independent assessment are discussed in terms of the relevance of documents, and standard retrieval policies are analyzed.…

Describes SENTINEL, a prototype information-retrieval system that is a fusion of multiple information-retrieval technologies, integrating n-grams, a vector space model, and a neural network training rule. Discusses three-dimensional visualization capability, precision and recall, mathematical representation of a document, query building, and…

Presents an approach to a Genetic Information Retrieval Agent Filter (GIRAF) that filters and ranks documents retrieved from the Internet according to users' preferences by using a Genetic Algorithm and fuzzy set theory to handle the imprecision of users' preferences and users' evaluation of the retrieved documents. (Author/LRW)

Reports the results of a study of users' perceptions of relevance of documents that focused on evaluating the effectiveness of a telephone-based information retrieval service. Studies how users' perceptions varied depending on the form in which retrieved documents were presented, from full text to a machine-spoken summary. (Contains 27…

Presents a unified mathematical definition for the classical models of information retrieval and identifies a mathematical structure behind relevance feedback. Highlights include vector information retrieval; probabilistic information retrieval; and similarity information retrieval. (Contains 118 references.) (Author/LRW)

Examines statistical techniques for exploiting relevance information to weight search terms. These techniques are presented as a natural extension of weighting methods using information about the distribution of index terms in documents in general. (Author)

Presents notations and definitions necessary to identify the concepts and relationships that are important in modelling information retrieval objects and processes in the context of vector spaces. Earlier work on the use of vector models is evaluated in terms of the concepts introduced and certain problems are identified. (Author/EM)

Instead of leaving the user at the point where he or she receives the information from the reference storage and retrieval system, we should follow him or her to see what the impact is from the information received, how it actually affects the user's performance in his or her task. (Author/PF)

A hypothetical methodology is presented for measuring retrieval effectiveness by using the personal utility, based on a user's subjective evaluation, of a retrieval system's output. Because the methodology is impractical, compromise methods are outlined and their underlying assumptions, which can serve as criteria for formulating appropriate…

Describes a study that used the TREC information-retrieval test collection to evaluate Visual Information Retrieval Interfaces (VIRIs). Discusses multiple-similarity measures, scaling properties, and MLE (maximum likely method), and suggests that cosine-vector and overlap measures for similarity appear to recover optimal data relationships among…