A model for an information retrieval system in which recall and precision are inversely related is described, and then the anomaly is resolved. (PF)

The Swets model of information retrieval as a decision theory model is reviewed. (Author)

Recently considerable attention has been given in the online information retrieval literature to techniques for producing a weighted output of documents in response to a request. One approach tries to maintain the form of and relationships among requests as they appear in current Boolean logic-based systems, while extending it to permit a weighted…

Suggests a new definition of relevance as it relates to information retrieval and compares the use of the term in theoretical models by Swets and by Maron and Kuhns. (FM)

Discusses the problem of how to permit a patron to represent the relative importance of various index terms in a Boolean request while retaining the desirable properties of a Boolean system. (FM)

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…

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)

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

The direct-chaining technique of hash coding is generalized in a manner that is useful for storing records on the basis of non-unique search keys. Two hash functions are used, a process implying a tree structure. Two models, one involving unique and the other non-unique keys, are presented. (7 references) (Author/KE)

Defines a hash coding model for non-unique search keys and derives the expected number of accesses needed to retrieve all desired records from a computer storage device. (Author)

An access method for bibliographic records that combines features of the search key approach and the inverted file approach. Permits extension of search key technique to large files. (Author/LS)

Discusses automated information retrieval, focusing on statistical patterns expected of a pair of terms that are semantically related to each other, guided by text generation conceptualization. Examines how the tendency of a content bearing term to clump, as quantified by previously developed measures of term clumping, is influenced by the…

Presents new methods for compressing bit matrices in large information retrieval systems which exploit possible correlations between rows of words and columns of documents. Three encoding methods are tested and compared--Shannon-Fano, arithmetic, and Huffman--and an appendix discusses binomial coefficients. (20 references) (LRW)