This article presents a model for the motion of a long-cane executing the touch technique and presents formulas for the projected length of a cane adequate to protect an individual with blindness against wall-type and pole-type hazards. The paper concludes that the long-cane should reach from the floor to the user's armpit. (JDD)

This set of transparencies shows how the manipulation of combinatorial structures in the context of modern combinatorics can easily lead to interesting teaching and learning activities at every level of education from elementary school to university. The transparencies describe: (1) the importance and relations of combinatorics to science and…

Direct and indirect effects in decomposed zero-order correlations among variables in causal models are considered. Under certain circumstances, the components of the decompositions could be interpreted as direct, indirect, and spurious causal effects, plus a component called joint associations. The sum of the direct and indirect effects is the…

In all latent trait models there is an equation which describes the probabilistic outcome of the interaction of a person with a known ability and an item with a known difficulty. This modeled outcome can be compared to the observed outcome, and the residuals can be summed over the items to assess the fit of the person to the model. Various…

The norm-referenced score scale used by the National Foundation for Educational Research (NFER) is described. The usefulness of standardized scores is explained by a simple numerical example, and the formulas and computations are shown for calculating a mean, a standard deviation, and a deviation or z score. The need for a representative sample is…

Examines the problem of aging of books in university libraries and presents a mathematical model of the aging process. Indexes for the aging time limit, over-age book rate, and aging rate are suggested; use of the mean unit price is considered; and countermeasures for control of the aging process are proposed. (four references) (MES)

This report examines New York State's experience with multi-element formulas in budgeting for the State University of New York, and considers some of the obstacles confronting scientific budgeting in a political environment. A specific budgeting formula (the Academic Discipline Model) is examined, its evolution and application discussed, and the…