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)

Considers the problem of allocation resources among various locations in an information system where phases of a process are carried out. Approach taken combines queueing theory and dynamic programming. (JB)

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

Describes the use of loglinear statistical models in the field of informetrics, especially for the analysis of information systems. A detailed example is given of developing a model based on loglinear analysis to determine book acquisition patterns in libraries, including mathematical considerations and algorithms. (19 references) (LRW)

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,…

Examines consequences for information control of the tendency of occurrences of content-bearing terms to appear together, or clump. Properties of previously defined clumping measures are reviewed and extended, and significance of these measures for devising retrieval strategies discussed. A new type of clumping measure, which extends the earlier…