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 application of the theory of fuzzy sets to the description of information retrieval systems makes it possible (1) to take into account the fact that the degree of importance of the particular terms is of a continuous character, (2) to formalize the relations between terms describing documents and information requests (fuzzy thesaurus).…

The model assumes that the relevance assigned to a document by a juror is a random variable. (PF)

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)

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)

Defines the scope and significance of the field of informetrics and relates it to the earlier fields of bibliometrics and scientometrics. Practical and theoretical aspects of informetrics are discussed, including the development of mathematical models and the derivation of measures; and a brief overview of articles in this issue is included. (15…

False drops occur in a system of random superimposed coding for edge-notched, punched, and feature cards. Formulae for the false dropping fraction are derived, and figures and tables are given for the calculated values in the most popular scheme. (Author/LS)

A new method for concentrating keywords of a thesaurus, based on a mathematical study of the distribution of characters in a defined natural language. (Author/KP)

Argues that most currently used information retrieval models are unsuitable to describe recent techniques such as semantic based retrieval. A more general model is presented in which the basis for information retrieval is viewed as logical implication and the estimation of the correspondence between queries and documents is described in terms of…

Presents the list-structure data model for dealing with sets of objects, which has ordering as its fundamental principle. An extended notion of patterns and several operators of the algebra are presented. Design issues that influenced the development of the language are described. (Contains 30 references.) (KRN)

Reports on the validity of the Multiple Poisson (nP) model of word distribution in full-text document collections. A practical algorithm for determining whether a certain word is distributed according to an nP distribution and the results of a test of this algorithm in three different document collections are described. (14 references) (KRN)

Presents a general mathematical framework for information retrieval, in which query evaluation is seen as a mapping from the free term algebra built by query descriptors and weights to the semantic algebra of evaluation value. Competing mathematical models that try to describe how retrieval systems behave are reviewed. (Author/MBR)

The approach of J. D. Sneed is used to argue for a distinction between theoretical and nontheoretical (or empirical) entities. Attention is directed toward this approach as an important facility for looking at statistics and for constructing a framework for the correct use of statistical theory in information retrieval experiments. (MBR)

Proposes an information retrieval model in which documents are characterized by a simple probability measure on the set of index terms, and describes two retrieval strategies, one based on utility theory and the other on information theory. The discussion covers experimental findings of retrieval effectiveness and insights into fundamental…

Presents a model that places Boolean database queries into conjunctive normal form, thereby allowing probabilistic ranking of documents and the incorporation of relevance feedback. Experimental results compare the performance of a sequential learning probabilistic retrieval model with the proposed integrated Boolean probabilistic model and a fuzzy…