A causal model of halo error (HE) is derived. Three hypotheses are formulated to explain findings of negative HE. It is suggested that apparent negative HE may have been misinferred from existing correlational measures of HE, and that positive HE is more prevalent than had previously been thought. (SLD)

Discusses bibliometric studies of research collaboration and describes the development of a theoretical model for the distribution of authorship. The shifted Waring distribution model and 15 other probability models are tested for goodness-of-fit, and results are reported that indicate the shifted inverse Gaussian-Poisson model provides the best…

A nonspatial operationalization of the Krumhansl distance-density model of similarity is presented. The conceptual model and empirical evidence are reviewed. A nonspatial, tree-fitting methodology is described, which is sufficiently flexible to fit several competing hypotheses of similarity formation. Extensions to spatial models, three-way…

An approach is presented for determining unidimensional scale estimates that are relatively insensitive to limited inconsistencies in paired comparisons data. The solution procedure--a minimum-cost network-flow problem--is presented in conjunction with a sensitivity diagnostic that assesses the influence of a single pairwise comparison on…

In Guttman-type quantification of contingency tables and multiple-choice data (incidence data), the trivial solution because of marginal constraints is typically removed before quantification. Relevant formulas are presented for cases affected by the trivial solution and those that are not. (SLD)

Results from 2 studies involving 52 and 57 adults, respectively, suggest that, when an intertemporal trade-off is embedded in 2 alternative sequences of outcomes, the psychological perspective (frame) shifts and individuals become more farsighted, often wishing to postpone the better outcome to the end. Implications for studying intertemporal…

A model is presented that demonstrates that a random response to external constraint can produce results similar to those predicted by more complex models. Behavior that appears rational, optimal, or adaptive may truly be a random response to external constraint. Predictions based on this model may provide appropriate null hypotheses. (SLD)

Studied whether the standard z-statistic that evaluates whether a factor loading is statistically necessary is correctly applied in such situations and more generally when the variables being analyzed are arbitrarily rescaled. An example illustrates that neither the factor loading estimates nor the standard error estimates possess scale…

An item response theory model based on the Rasch model is proposed for composite tasks, those decomposed into subtasks of different kinds. The model, which is illustrated with an application to spelling tasks, constrains the difficulties of the composite tasks to be linear combinations of the difficulties of the subtask items. (SLD)

Although data is often used to estimate parameters for models in calculus and differential equations, the models themselves are seldom justified. Uses the data itself to motivate mathematical models in introductory mathematics courses. Illustrates various regression and optimization techniques. (Author/ASK)

Estimates a college-attendance equation for a common set of students (from the High School and Beyond Survey) using three popular econometric specifications: the multinomial logit, the ordered probit, and the bivariate probit. Estimated marginal effects do not differ significantly across the three specifications. Choice of specification may not…

Using 1990-91 data for 143 Ph.D. granting institutions, this study applies a simultaneous equation model to determine whether an institution's amount of research grants is a function of its academic ranking. Results show a simultaneous relationship among grants per full-time-equivalent enrollment, institutional ranking, and graduate students as a…

Defines a mathematical model of uniform response bias (URB) and proposes ipsative measures to minimize the effect of URB in multigroup confirmatory factor analysis. Illustrates the method using real data from the Chinese Personality Assessment Inventory for 2 groups of sample sizes 793 and 792 adults. (SLD)

Reports on a study comparing the use of Multi-base arithmetic blocks (MAB) and an alternative, LAB (linear arithmetic blocks) on the basis of epistemic fidelity and accessibility for students. Use of LAB was associated with more active engagement by students and deeper discussion. (Author/MM)