An evaluation of the rules-of-thumb used to determine the minimum number of subjects required to conduct multiple regression analyses suggests that researchers who use a rule of thumb rather than power analyses trade simplicity of use for accuracy and specificity of response. Insufficient power is likely to result. (SLD)

Forming the matching variable for the Mantel-Haenszel differential item functioning (DIF) procedure through use of the total score as the matching variable (thin) and forming the matching variable by pooling total score levels (thick) were compared in a Monte Carlo study. Reasons thick matching is superior are discussed. (SLD)

Reevaluates statistical studies by G. Galster (1986, 1987, 1988) and Galster and W. Keeney (1988) of segregation in housing, reanalyzing one of four model equations. The effects of discrimination are smaller than postulated previously. Direct estimates from housing discrimination surveys provide a rationale for these smaller effects. (SLD)

Analyzes effect sizes in tails of distribution of scores in Feingold's study of joint effects of gender differences in mean and variability on 28 cognitive-ability scales. Effect sizes are smaller than Feingold assumed. Evaluates joint effect of gender differences by number of males and females in extreme score ranges. (SLD)

Discusses the surprising result that the expected number of marbles of one color drawn from a set of marbles of two colors after two draws without replacement is the same as the expected number of that color marble after two draws with replacement. Presents mathematical models to help explain this phenomenon. (MDH)

Studied effects of students' use of calculators with 2 experimental forms of a university mathematics test taken by 765 and 725 college students, respectively. Calculator effects are not found for overall scores but are seen for some individual items. Analysis at the item level makes the actual impact apparent. (SLD)

Statistical approaches to assess how prevention and intervention programs achieve their effects are described and illustrated through the evaluation of a health promotion program to reduce dietary cholesterol and a school-based drug prevention program. Analyses require the measurement of intervening or mediating variables to represent the…

Discusses a pedagogical approach to calculus based on the question: What kinds of problems should students be able to solve? Includes a discussion of types of problems and curriculum threads for such a course. Describes a projects-based calculus with examples of projects and classroom activities. (Author/MDH)

This paper illustrates how, in the item-response theory framework, collateral information about test items can augment or replace examinee responses when linking or equating new tests to established scales, using data from the Pre-Professional Skills Test for approximately 40,000 examinees. Collateral information can predict item operating…

A study used correlational analysis and step-wise multiple regression to build mathematical models representing the dynamics of student evaluation of courses and teachers. The resulting models were very strong and were subsequently used to improve academic programs in Kuwait's Institute of Banking Studies. (Author/MSE)

Children's responses to an alternative model over three lessons were described and their learning assessed in a posttest. Their responses and performances were compared to that of a similar group of children learning through a conventional number line model. The two models were compared from practical and theoretical viewpoints. (Author/CW)

Two extensions of the Mantel Haenszel procedure that may be useful in assessing differential item functioning (DIF) are explored. Simulation results showed that, for both inferential procedures, the studied item should be included in the matching variable, as in the dichotomous case. (SLD)

Highlights an activity that focuses on learning the geometric concepts needed for students to design blueprints for a city park by mastering fifth-grade geometry concepts and applying their knowledge in a real-world context. (ASK)

Presents a computer-mediated discourse on the Pythagorean equation in a university classroom of preservice and inservice teachers. Shows how the use of a spreadsheet as a two-dimensional modeling tool enables students to conjecture the general solution to the Pythagorean equation. Argues that a computational approach to the ancient problem…

Identifies market and nonmarket returns to education over graduates' life cycle, as well as social benefit externalities. Considers most recent developments in measuring and evaluating these returns, relating them to costs. The capacity to finance lifelong learning depends on identification and measurement capacity and political processes. (149…