Linear ciphers, substitution ciphers, public-key cryptosystems, and trapdoor knapsacks are each discussed. (MNS)

A prescriptive theory of teaching based upon an information processing model of human functioning is outlined. Based on teaching functions, defined as necessary conditions of learning, a general teaching algorithm is presented and its use demonstrated. (Author/MT)

Using examples of data from the areas of information retrieval and of multivariate data analysis, six hierarchic clustering algorithms (single link, median, centroid, group average, complete link, Wards's) are examined and evaluated by using three proposed coefficients of hierarchic structure. Nine references are cited. (EJS)

The algo-heuristic theory is concerned with identifying unobservable cognitive processes and their unconscious component cognitive operations, including learning how to describe them algorithmically and heuristically, and how to devise specific instructional tools (algorithmic and heuristic) to develop cognitive processes much faster. (BW)

The implications of some major linguistic and semiotic concepts for the machine manipulation of natural language text are examined. It is proposed that the study of meaning should contribute to the development of sophisticated algorithms for machine indexing. (Author)

A review of the literature reveals that important statistical algorithms and indices pertaining to logistic regression are being underused. This paper describes logistic regression in comparison with discriminant analysis and linear regression, and suggests that some techniques only accessible through computer syntax should be consulted in…

The design of programs to search large document data bases is discussed with regard to the use of compression coding combined with adoption of word fragments as the basic language elements. An algorithm is described for determination of a set of almost equifrequent fragments. Its efficiency is tested. (23 references) (Author)

The problem of getting a correct result when a fraction is reduced by cancelling a digit which appears in both the numerator and the denominator is extended from the base ten situation to any number base. (DT)