Investigates the use of mathematical modeling tasks in 11- and 12-year-old students and the development of mathematical thinking skills using practical modeling activities. Analyzes the development of students' mathematical thinking with interviews of a form of dynamic assessment. Reports that some students proved to be naturally mindful and…

Examines four areas of difficulty with graphing and modeling, identifies confusions and misconceptions, and shows how these areas interact in the presence of data-collection devices. (KHR)

Describes a simulation using dice-tossing students in a population cluster to model the growth of cancer cells. This growth is recorded in a scatterplot and compared to an exponential function graph. (KHR)

Describes a rugby problem designed to help students understand the maximum-minimum situation. Presents a series of explorations that locate an optimal place for kicking the ball to maximize the angle at the goalposts. Uses interactive geometry software to construct a model of the situation. Includes a sample student activity. (KHR)

Describes a credit-card-debt activity that allows students to increase their awareness of underlying mathematical concepts relevant to the world of commerce and personal finance through learning geometric and arithmetic sequences. (KHR)

Reports on a research project to use transformation geometry to give students an opportunity to work with proportions using visual models. (YDS)

Draws on data from 1988 National Education Longitudinal Study to estimate the impact of block-scheduled mathematics course on 10th-grade student achievement and teachers' use of class time. Findings suggest that while block scheduling is positively associated with teachers' use of multiple instructional methods and more individualized instruction,…

This paper evaluates the effectiveness of self-deferral, a social screen implemented to protect the U.S. blood supply from human immunodeficiency virus (HIV) infection prior to the advent of laboratory testing. Mathematical models are developed to estimate the number of infectious transfusions ultimately leading to AIDS prior to self-deferral.…

A methodology for calculating the return on training investment is described. The method covers attitudes, knowledge, and behavior of participants as well as effectiveness in organizational improvement. Output, time savings, quality improvements, and "soft data" on effectiveness are set against costs. (TJH)

A method is proposed for the detection of item bias with respect to observed or unobserved subgroups, using a loglinear item response theory model assuming a Rasch model for ability and difficulty. A simulation study was performed with 200 sets of data to check the robustness of the method. (SLD)

Data on National Direct Student Loan Program borrowers at the University of North Carolina illustrate the use of a discriminant function analysis model and an alternative model identifying characteristics of borrowers who repay and borrowers who default. The alternative model--the Tobit technique--includes data on the magnitude of the default.…

Discusses the use of a computer-illustrated text (CIT) with integrated software to teach electric circuit theory to college students. Examples of software use are given, including simple animation, graphical displays, and problem-solving programs. Issues affecting electric circuit theory instruction are also addressed, including mathematical…

The effects of certain characteristics (e.g., sample design) of National Assessment of Educational Progress (NAEP) data on statistical analysis techniques are considered. Ignoring special features of NAEP data and proceeding with a standard analysis can produce inferences that underestimate the true variability and overestimate the true degrees of…

The developmental trend from overall-similarity to dimensional-identity classifications is explained by a quantitative model. The model provides good qualitative fits to the extant data. Three experiments examining classifications in 120 2- to 8-year-olds and in 20 undergraduates support specific new claims of the model. (TJH)

Covariance structures associated with linear structural equation models are discussed. Algorithms for computing maximum likelihood estimates (namely, the EM algorithm) are reviewed. An example of using likelihood ratio tests based on complete and incomplete data to improve the fit of a model is given. (SLD)