A model is proposed to explain the retrieval characteristics of an information retrieval system. (Author)

Explores the properties of independent variables in information retrieval systems and defines a class of basic variables named M-factors. (Author/PF)

Suggests that a possible reason for receiver-operating characteristics (ROC) curves having a slope other than unity when plotted on Normal-deviate axes is that the dichotomy into relevant and nonrelevant items is artificial, and that there is really a bivariate distribution of objective relevance and relevance as assessed by the information…

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)

Presents decision-theoretic models which intrinsically include retrieval of multiple documents whereby system responds to request by presenting documents to patron in sequence, gathering feedback, and using information to modify future retrievals. Document independence model, set retrieval model, sequential retrieval model, learning model,…

Presents a mathematical model of an information retrieval system thought to be general enough to serve as an abstract representation of most document and reference retrieval systems. The model is made up of four components that, in one form or another, appear in every functioning system. (Author)

This paper is concerned with the organization and retrieval of records in document retrieval systems which admit of imprecision in the form of fuzziness in document characterization and retrieval rules. A mathematical model for such systems, based on the theory of fuzzy sets, is introduced. (Author)

The transfer of information through space and time in communication systems is often accompanied by significant delays which give rise to meaningful storage problems. Mathematical models have been developed for the study of these kinds of problems which are applicable to the design of manual, library-type, or mechanized information storage and…

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.…

A model of word occurrences in documents is presented in the context of a model information system. (Author/PF)

Using abstract models of thesaurus-based and multi-attribute retrieval systems a correspondence between the two systems is established so that equivalent transformation of problem statements expressed by notions developed for one system into problem statements expressed by notions pretaining to the other one may be effectively constructed. (5…

The theoretical model of a document retrieval system is described by giving logical meaning to the vagueness and the similarity characteristic to such systems, with the frequency of occurrences of keywords and the relations among them taken into consideration. (6 references) (Author/SJ)

A Mathematical model for use in studying how to minimize the cost of operating a mechanized retrieval system is developed. Through the use of cost analysis, the model provides a method for comparative evaluation between information retrieval systems. (15 references) (Author/SJ)

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…