The way in which trait and rater variance combine in multitrait-multirater (MTMR) performance appraisal data is explored. Implications of the confirmatory factor analytic model and the composite direct product (CDP) model for MTMR data are examined. Superior fit of the CDP model for four data sets is discussed. (SLD)

Presents an activity to investigate the dimensions of the maximum rectangular area given a fixed perimeter using mathematical modeling and manipulative materials. Students collect and compare data, find patterns, graph data, write functions, and discuss the meaning of the related mathematical model. Provides three reproducible worksheets for the…

Type I error rates for Yao's, James' first-order and second-order, and Johansen's tests of equality of mean vectors for two independent samples were estimated for various conditions defined by the degree of heteroscedasticity and nonnormality. Each procedure can be seriously nonrobust with exponential and log-normal distributions. (TJH)

Equating error was estimated using the same test with three linear equating methods in three paradigms--single-link equating; circular equating through a chain; and pseudo-circular equating, in which a test is equated to itself through equating chains. Over 31,000 Psychometric Entrance Test scores of college applicants in Israel were analyzed.…

Confluence theory was developed to explain the negative effects of birth order on intelligence. Using aggregate, between-family, within-family, and paired-sibling data from the Wisconsin Longitudinal Study, tests the mathematical form of confluence theory and finds no support for it. Suggests that statistical methods used to fit the model to the…

An activity designed as an introduction to High School geometry empowering students to see relationships and make geometric connections. A list of student generated relationships based on student constructed and manipulated diagrams is included. Discussion guidelines are suggested. (DE)

Presents an activity for introducing probability by investigating the Chinese policy of having one child per family and a one-son policy of some rural Chinese. Discusses features of the problem, including counterintuitiveness, multiple options for analysis, and thought experiments. (MKR)

Discusses an activity which models the building of a tunnel by ants using the definitions of derivative and indefinite integral from calculus. Includes a discussion of reasonableness and interpretation of the problem. (MKR)

A detailed investigation is provided of Stout's statistical procedure (the computer program DIMTEST) for testing the hypothesis that an essentially unidimensional latent trait model fits observed binary item response data from a psychological test. Three refinements achieve greater power. The revised approach is validated using real data sets.…

Builds a model explaining the behavior of the supply and demand for education at U.S. liberal arts colleges. A statistical analysis of 1990-91 data for 338 private liberal arts institutions suggests a perfectly competitive market. Student quantity, costs, test scores, class size, and college rankings help explain tuition variations. Contains 27…

Estimates a fixed-effects model of pay determination for five Ph.D.-granting departments of economics in large midwestern state universities. Departments' reward structures vary widely. Second sabbatical leaves are associated with higher pay. In estimating rewards for research, returns to quality overwhelm returns to quantity at four universities.…

This special issue was inspired by Greg Duncan and Saul Hoffman's 1981 article on the "incidence and wage effects of overeducation." These researchers used a Mincer earnings equation to determine that a substantial number of American workers were over- or under-educated for their chosen occupations. (MLH)

Describes the construction of an exponential decay graph that can be used in a science class to support discussions about the uses of radioactivity, its risks, limitations, and advantages. (WRM)

A major cause of the difficulty undergraduate mathematics majors have with the transition from elementary to advanced mathematics courses is that advanced courses require students to understand how mathematics is created. Describes a course whose main purpose is to introduce students to the creative process in mathematics. The course consists of…

Explores whether state policies encouraging the consolidation of rural school districts to improve efficiency through economies of scale are substantiated in the research literature. Reviews three decades of research on education economies of scale involving cost and production-function studies. Finds little program-evaluation research on school…