Proposes an alternative methodology for handling queries with weighted search terms or search criteria in a fuzzy environment as a means of improving the performance of information retrieval systems. (EM)

Retrieval experiments with the Cranfield collection of 1,400 documents used strategies based on a probabilistic model for an initial search and intermediate search when no relevant documents were known. Results show initial strategy is better than conventional strategies in retrieval effectiveness and number of queries needed to retrieve…

Five models which perform search tasks of the Data Base Access and Search Environment (DBASE) are presented and used for comparison with subject search performance--unconstrained (rule-based, decision theoretic) and constrained (optimal rule-based, rule-based, probabilistic rule-based). Previous experiments and the modeling approach are briefly…

Describes an iterative method of document retrieval similar to relevance feedback in that user feedback is utilized in subsequent iterations. However, this method compares retrieved documents with each other using algebraic formulae which determine the boundaries of the area that contains descriptions of relevant documents. Fifteen references are…

Presents a dynamic model of user behavior when scanning an information storage and retrieval system output list, compares rules for determining the user's optimum stopping point, presents an algorithm for implementing the Bayesian model, and discusses implications for retrieval system design. Provided are 13 figures and 15 references. (Author/RBF)

Explores potential of mathematical theory of communication for information science and examines question of how to encode a message at time it is encountered for subsequent recall. Examples of problem, a prototype computer program and experiment, coding as embedding in associational nets, and nature of information are discussed. (Nine references.)…

The mathematical model proposed describes a computerized bibliographic information system which includes a method--document learning--of improving the set of index terms assigned to a document representative. Inputs to the information system (index terms and query), relevance feedback, and assumptions concerning the model are discussed.…

Presents an analytical approach to the interpretation of weighted Boolean queries. By distinguishing query term weights from query weights, a query becomes a means of describing classes of ideal documents and expressing relativity criteria among these descriptions. A formalization of query term weights is given in a fuzzy set theoretical context.…

Data on 2,380 searches of online information retrieval systems are analyzed using a mathematical model to determine the relationship between two measures of effectiveness--documents read and relevant references. The nature and relative merits of these two variables are discussed, as well as the findings, and seven references are listed. (RBF)

Discusses several query-processing methods designed to allow the use of relevance weights or thresholds attached to terms and compares them with normal Boolean rules and fuzzy subset theory. Forty-five references are listed. (FM)

Provides a method for estimating precision without examining individual database documents, which requires knowledge of only the query or expressed information need and a set of database parameters constant for all queries. Concepts of historic and expected precision are examined, and applications of precision-document graphs are assessed. (36…

Describes the Waller-Kraft "wish list" of desired information retrieval system properties and identifies ambiguities caused by two distinct uses of the phrase "query term weight." Examples of problems arising from the ambiguity are given and a new list is created and discussed. (10 references) (Author/CLB)

Various models that have been devised to evaluate the performance of information retrieval systems are reviewed. Such models fall into three categories: (1) evaluation from the viewpoint of the user, who is primarily concerned with how well the system responds to his query; (2) evaluation from the system operator's standpoint, which focuses on the…

A comparative study of the cost effectiveness of retrospective manual and on-line bibliographic searching is described. Individual task times for question analysis, searching, photocopying, shelving and output distribution were measured, and component costs for labor, information, reproduction, physical space and telecommunications calculated. The…

Presents data model based on text data model (TDM), universal relation model, and nonfirst normal form (NFNF) relations, and discusses applicability to text processing and document retrieval systems. Highlights include database technology applied to information retrieval, NFNF and universal relation, and TDM integration with NFNF universal…