A weighted Euclidean distance model is proposed that incorporates a latent class approach (CLASCAL). The contribution to the distance function between two stimuli is per dimension weighted identically by all subjects in the same latent class. A model selection strategy is proposed and illustrated. (SLD)

Research on the direct-product model is extended by deriving hierarchically nested models for explicitly testing the patterns of method and trait factors and through formal tests developed for the pattern of communalities. These procedures are illustrated, and use of the MUTMUM computer program is discussed. (SLD)

Coefficient alpha was examined through computer simulation as an estimate of test reliability under violation of two assumptions. Coefficient alpha underestimated reliability under violation of the assumption of essential tau-equivalence of subtest scores and overestimated it under violation of the assumption of uncorrelated subtest error scores.…

R. A. Bailey and J. C. Gower explored approximating a symmetric matrix "B" by another, "C," in the least squares sense when the squared discrepancies for diagonal elements receive specific nonunit weights. A solution is proposed where "C" is constrained to be positive semidefinite and of a fixed rank. (SLD)

Several metanalytic studies of group variability use variance ratios as measures of effect size. Problems with this approach are discussed, including limitations of using means and medians of ratios. Mean logarithms and the geometric mean are not adversely affected by the arbitrary choice of numerator. (SLD)

Effects of overextracting factors and components within and between maximum likelihood factor analysis and principal components analysis were examined through computer simulation of a range of factor and component patterns. Results demonstrate similarity of component and factor scores during overextraction. Overall, results indicate that…

Whether it is possible to develop a classification function that identifies the underlying range restriction from sample information alone was investigated in a simulation. Results indicate that such a function is possible. The procedure was found to be relatively accurate, robust, and powerful. (SLD)

Discussion of journals and the nature of their interrelationships focuses on a loglinear model of citation frequency that allows an examination of the influence between journals of related disciplines. Multidimensional scaling (MDS) is described, and an example using the Social Sciences Citation Index (SSCI) and journals relating to marketing is…

Develops the formulas for the sum of the numbers from 1 to n and for the squares of the numbers from 1 to n geometrically by utilizing the formulas for the area of a triangle and the volume of a pyramid. (MDH)

A numerical approach for computing standard errors (SEs) of a linear equating is described in which first partial derivatives of equating functions needed to compute SEs are derived numerically. Numerical and analytical approaches are compared using the Tucker equating method. SEs derived numerically are found indistinguishable from SEs derived…

This article shows how a multivariate approximate degrees of freedom procedure based on the Welch-James procedure as simplified by S. Johansen (1980) can be applied to the analysis of repeated measures designs without assuming covariance homogeneity. A Monte Carlo study illustrates the approach. (SLD)

Analyzes propensity of business school alumni to give cash donations to their alma mater. Estimates a utility maximization model, using logistic regression and survey sample data of 1956-90 graduates of a large U.S public research university. Giving probability is strongly correlated with specific majors, time since graduation, other factors.…

A Fisher's Z transformation is developed for the corrected correlation for conditions when the criterion data are missing because of selection on the predictor and when the criterion was missing at random, not because of selection. The two Z transformations were evaluated in a computer simulation and found accurate. (SLD)

"Composition analysis" refers to the mathematics of how component measures combine to produce composite measures based on Bookstein's functions. Composition analysis is applied to the different ways group members might work together such that their individual measures can be combined mathematically to calculate an expected measure for…

This article presents an extended version of the convolution-correlation memory model TODAM (theory of distributed associative memory) that eliminates some inadequacies of previous versions and provides a unified treatment of item, associative, and serial-order information. TODAM2 extends the chunking model to provide a general model for episodic…