In this article, the author focuses on possible ways to develop the concepts of joint variation and function through the upper primary and lower secondary years of education. The examples demonstrate the building of a range of important mathematical ideas by modelling life-related situations using students' informal and intuitive knowledge. Over…

The never-ending organizational challenge is to allocate available resources to best achieve its goals. Out of this fundamental question several models have evolved. One is a conceptual model--a way to think about how organizations operate. A second is a statistical model estimating the magnitude of relationships among goals and elements of the…

This article describes the use of digital images of real-life phenomena and interactive software to carry out mathematics investigations. (Contains 13 figures.)

A mathematical model of working-memory capacity limits is proposed on the key assumption of mutual interference between items in working memory. Interference is assumed to arise from overwriting of features shared by these items. The model was fit to time-accuracy data of memory-updating tasks from four experiments using nonlinear mixed effect…

A new mathematical tool, known as Engage, Explore, Explain (EEE) model, was developed that was simple for teachers to use, could guide them as they planned exploratory experiences, and was useful to teach mathematics for understanding. The EEE model provides a lesson structure for teachers to use with almost any mathematics topic and can easily be…

Hypotheses that do not have the standard bilinear form theta=CBM=0 occur naturally in the analysis of repeated measurement designs. An expanded class of the tests of the form psi=Tr(G theta)=0, called extended linear hypotheses, provides a richer class of parametric functions. A method to analyze double multivariate and mixed multivariate models…

Methods for the path analysis of complex (i.e., not fully recursive) causal models are briefly discussed. A computer program which simplifies analysis of such models and provides an option for automatically deleting marginal paths is described. (Author)

This article is divided into three main sections. The first addresses the problems associated with the present use of the linear model. The second provides some empirical evidence to help strengthen the arguments made against the model, and the third offers some alternatives along with suggestions for their implementation. (Author/DEP)

The binary search scheme is a method of finding a particular file from a set of ordered files stored in a computer. In this article an exact expression for the expected number of passes required to find a file is derived. (Author)

Gives a model to interrelate the measures of service used in a library. (Author/PF)

The use of indices of speededness in tests is reviewed and three possible indices which derive from a model which assumes that rate of work is normally distributed is proposed. Each of these indices is seen as limited by the failure to adequately consider the correlation between speed and power, but they have the advantage that they are derivable…

The defining property of an admissible scoring system is that any individual perceives himself as maximizing his expected score by reporting his true subjective distribution. The use of admissible scoring systems as a measure of probabilistic forecasts is becoming increasingly well-known in those cases where the forecast is a discrete distribution…

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)

The purpose of this study is to develop statistical tests for within cluster homogeneity when objects are scored on binary variables. (DEP)

The outbreak of research on "anomalous water," or "polywater," from 1962 to 1974 provides an interesting opportunity for testing the epidemic theory of idea dissemination. (Author)