Several models of grading variability are presented. It is shown that study of the models brings out some of the implications of various grading systems. (MK)

Using covarient harmonic oscillator formalism as an illustrative example, a method is proposed for illustrating the difference between the Poincare (inhomogeneous Lorentz) and homogeneous Lorentz groups. (BT)

Techniques for digitalizing analog signal data are presented and compared. The techniques presented are: boxcar averaging, ensemble averaging, unweighted digital filter, weighted digital filter, and analog filter. (BB)

Logistic analysis of black journal articles suggests that black American publications have passed through cycles of intellectual interest." (Author/JM)

Directions are given for making a model of a three-dimensional coordinate graph. (DT)

A structural equation model for attitude-behavior relationships is presented which conceptualizes attitude scales as congeneric measurements. The model represents a re-parameterization of an earlier one. (Author/RC)

A longitudinal program evaluation approach used in the Vermont system of care for children and adolescents is described. The method focuses on movement between residential placements and compares system functioning to service system values using a person-level longitudinal database. This methodology can be useful in a number of fields. (SLD)

Proposes a mathematical way of thinking about how well a rolling object moves. Describes classroom activities that were carried out to measure and evaluate models of rolling objects. In theory, the activities lead immediately to the theory of convex sets. Also includes discussion on Reuleaux rollers. (AIM)

Presents a model of what it means to understand mathematics followed by examples of exercises designed to develop understanding in specific ways. Presumes that understanding is more likely to develop if it is the direct focus of exercises. (AIM)

Shows how attention to transcending functions provides a new integrative approach to mathematics that can improve the critical thinking and problem-solving skills required for addressing large-scale problems. Contains 38 references. (DDR)

Explores the relationship between learners' actions, visualizations, and the means by which these are articulated. Describes a microworld called Mathsticks which is designed to help students construct mathematical meanings by forging links between the visual and symbolic representations they develop and their actions. Presents a case study of two…

Basic philosophical and statistical issues in structural equation modeling (SEM) are reviewed, including model conceptualization, identification, and parameter estimation and data-model-fit assessment and model modification. These issues should be addressed before the researcher uses any of the new generation of SEM software. (SLD)

A model projecting school enrollment by using births lagged an appropriate number of years and a model using lagged births and the previous year's enrollment were applied to two school grade levels and state and county levels in Kentucky. The model using lagged births and earlier figures provided better predictions. (SLD)

Studied modeling individual latent growth curves of older adults on measures of fluid intelligence by fitting second-order polynomial curves reflecting initial test performance improvement followed by relative stability/drop to the recorded scores of each of 248 subjects. Results suggest substantial plasticity in fluid intelligence of older…

Presents a typical cost-allocation problem with possible solutions, including geometric and combinatoric ones. Provides students with a real-life application of the mathematics that they know. (KHR)