A method for hierarchical agglomerative polythetic (multivariate) clustering, based on unweighted pair group using arithmetic averages (UPGMA) is compared with the original beta-flexible technique, a weighted average method. Reasons the flexible UPGMA strategy is recommended are discussed, focusing on the ability to recover cluster structure over…

How longitudinal factor score estimation--the estimation of the evolution of factor scores for individual examinees over time--can profit from the Kalman filter technique is described. The Kalman estimates change more cautiously over time, have lower estimation error variances, and reproduce the LISREL program latent state correlations more…

The effect of scale selection on error in calibrating item and ability parameters was investigated, with particular reference to the standardized mean-squared difference (SMSD) statistic. Through simulation, three scaling methods for selecting the common scale were used to demonstrate their effects on SMSD values. (SLD)

Characterizations of local homogeneity and the homogeneous monotone item response theory (IRT) model are provided. The characterization theorem states that the joint condition of experimental independence and pairwise nonnegative association in every nonnegligible subpopulation is necessary and sufficient for the homogenous monotone IRT model.…

The problem of chance model modifications under varying levels of sample size, model size, and severity of misspecification in confirmatory factor analysis models was examined through Monte Carlo simulations. Findings suggest that practitioners should exercise caution when interpreting modified models unless sample size is quite large. (SLD)

Uses a population-ecology approach to examine whether bureaucratic rules breed more rules. Tests hypotheses about rule births with time-series data on rule production in a large United States research university. Results show that the rate of rule production declines with the number of rules in a rule population over time. Rules inhibit…

Describes a new theory of likelihood judgments based on D. L. Hintzman's (1984, 1988) MINERVA2 memory model. The model, MINERVA-DM (decision making), accounts for a wide range of likelihood-judgment phenomena. Extends the model to expert-probability judgment and shows how MINERVA-DM can account for both good and poor calibration (overconfidence)…

Describes the Mathematical Contest in Modeling (MCM), a contest in which teams of three undergraduate students compete with other undergraduate teams from schools all over the world. Implements MCM at Eastern Oregon University and indicates that the MCM program promotes teamwork and generates enthusiasm in students. (Author/ASK)

Generating a test from an item bank using a criterion based on classical test theory parameters poses considerable problems. A mathematical model is formulated that maximizes the reliability coefficient alpha, subject to logical constraints on the choice of items. Theorems ensuring appropriate application of the Lagragian relation techniques are…

Graphing and statistics software permitting users to fit polynomial curves to scatter plots of data may display the equation generating the curve with numerical coefficients that have been rounded off to a few decimal places. The round-off error can produce anomalous findings due to systematic and extreme distortions of the fitted curve.…

Presents a LISREL model for the estimation of the repeated measures analysis of variance (ANOVA) with a patterned covariance matrix. The model is demonstrated for a 5 x 2 (Time x Group) ANOVA in which the data are assumed to be serially correlated. Similarities with the Statistical Analysis System PROC MIXED model are discussed. (SLD)

It is argued that the reduction of cognitive dissonance can be viewed as a constraint satisfaction problem, and a computational model of the process of consonance seeking is proposed. Simulations from this model matched psychological findings from the insufficient justification and free-choice paradigms of cognitive dissonance theory. (SLD)

Discusses the relationships between physical, mathematical, and mental models in the process of constructing and understanding physical theories. Attempts to interpret research findings with college students regarding mental models and physics education under the framework of Johnson-Laird's mental model theory. (Author/MM)

Describes the introduction of the Modelling Track in a Mathematical Engineering curriculum as a response to the employers' complaints about Dutch graduates' poor ability to apply theoretical knowledge. Describes the introduction of Design Based Learning (DBL), meaning professionalization, activation, co-operation, creativity, integration and…

Open-set word and sentence speech-perception test scores are commonly used as a measure of hearing abilities in children and adults using cochlear implants and/or hearing aids. These tests ore usually presented auditorily with a verbal response. In the case of children, scores are typically lower and more variable than for adults with hearing…