An attempt to replicate the results with averaged evoked potentials (AEPs) of D. E. Hendrickson and A. E Hendrickson (1982) with 40 adults confirms a negative correlation between AEP variability and IQ. The Hendrickson paradigm is seen as no more than a well-controlled auditory evoked potential. (SLD)

Compares probabilistic models of same-different and identification judgments concerning their sensitivity to perceptual dependence or the degree to which underlying psychological dimensions are correlated. Results support a perceptual independence assumption when using these models and pertain to studies of different decision rules used at…

A family of coefficients of relational agreement for numerical scales is proposed, generalizing to multiple judges the theory of F. E. Zegers and J. M. F. ten Berge (1985) of association coefficients for two variables, using the premise that choice of coefficient depends on scale type of the variables. (SLD)

The interpretation of discriminant functions as a follow-up to a significant multivariate analysis of variance is discussed. New indices are proposed that aid in identification and interpretation of the subset of response variables that contribute to a significant group discrimination. Their efficacy is compared to several commonly used…

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)