The sensitivity of marginal maximum likelihood estimation of item and ability (theta) parameters was examined when prior ability distributions were not matched to underlying ability distributions. Thirty sets of 45-item test data were generated. Conditions affecting the accuracy of estimation are discussed. (SLD)

A Monte Carlo study investigated the use of four cross-validation indices with confirmatory factor analysis models. Influences of sample size, loading size, and degree of model misspecification were studied. Larger sample sizes and better specified models result in better cross-validation results. (SLD)

A crossed random effects model is presented that applies to data with a nested structure to provide maximum likelihood estimates through the EM algorithm. The procedure is illustrated in studies of neighborhood and school effects on educational attainment in Scotland and classroom effects on mathematics learning in the United States. (SLD)

A conceptual framework is provided for thinking about measurement invariance (or bias), and conditions are demonstrated under which invariance can occur. Tools are suggested for addressing such issues as fairness in employment testing, salary equity, and cross-sectional developmental change. Strict factorial invariance is required for…

Inference is considered for the marginal distribution of "X" when ("X", "Y") has a truncated bivariate normal distribution. The "Y" variable is truncated, but only the "X" values are observed. A sample of 87 Otis test scores is shown to be well described by this model. (SLD)

Describes the Chemistry Visualization (ChemViz) Project, a Web venture maintained by the University of Illinois National Center for Supercomputing Applications (NCSA) that enables high school students to use computational chemistry as a technique for understanding abstract concepts. Discusses the evolution of computational chemistry and provides a…

Develops an approach for setting performance targets for schoolchildren, using data-envelopment analysis to identify benchmark pupils who achieve the best observed performance (allowing for contextual factors). These pupils' achievement forms the basis of targets estimated. The procedure also identifies appropriate role models for weaker students'…

Evaluates efficiency of a sample of Spanish secondary schools, focusing on the measurement model's theoretical specification and the "ex post" analysis of results. Highlights characteristics that differentiate the most efficient schools from the least efficient. Stresses the importance of employing information supplied by both…

Features an assignment involving average monthly temperatures that can serve as an example of curve-fitting for a periodic function. (WRM)

Uses a (spatial-econometric) location weighing variable to examine how starting teacher salaries in one Ohio district are influenced by other regional starting salaries. A $1 increase in a neighboring district generates a $.51 to $.96 increase. Size and distance factors help account for spill-over effects. (Contains 34 references.) (MLH)

Presents activities to model dynamic systems using graphing calculators and calculator based laboratories. (Author/ASK)

Describes a lesson that provides an opportunity for students to obtain the equation for a line describing data they have collected, use the equation they have derived to set up an Egg Bungee Jump, and relate the numbers in the equation to the physical properties of the bungee jump. (WRM)

Using a recruitment test for Korean teachers, the use of the Rasch measurement model to control the effects of judge variable on the grading of essay-type items is examined. Ways of minimizing the variation of grading due to judge severity and reducing the number of judges without threatening objectivity of ability measurements are presented.…

Presents model for estimation of student unit costs and staffing requirements. Begins with specification of a "staff distribution matrix" setting out proportions of staff levels in a given staff category that are needed for a degree level. Student unit cost and staffing requirements are computed through manipulations on the matrix. The…

Describes two activities to analyze unit-cell structures from a geometric viewpoint and invites students to apply their mathematical understanding to scientific phenomena. Students form models of the simple cube, a building block of crystalline structures, and a methane molecule. (MKR)