We explored the mediating role of prior knowledge on the relation between intelligence and learning proportional reasoning. What students gain from formal instruction may depend on their intelligence, as well as on prior encounters with proportional concepts. We investigated whether a basic curriculum unit on the concept of density promoted…

A reverse engineering approach to automatic item generation (AIG) was applied to a figure-based publicly released test item from the Organisation for Economic Cooperation and Development (OECD) Programme for International Student Assessment (PISA) mathematical literacy cognitive instrument as part of a proof of concept. The author created an item…

Studies of group differences in intelligence often invite conclusions about groups in general from studies of group differences in selected populations. The same design is used in the study of group differences in other traits as well. Investigators observe samples from two groups (e.g. men and women) in some accessible population, but seek to…

In longitudinal studies data is collected in a series of waves. Each wave after the first suffers from attrition. Therefore it can be difficult to discriminate between changes in sample parameters due to a longitudinal process (e.g. ageing) and changes due to attrition. The problem is particularly vexing if one of the purposes is to compare…

Applies the confluence model to a longitudinal intact family data set. Also tests the data with simple linear models. Results suggest that the confluence model should be rejected as a useful model for these data based on principles of parsimony and predictability. (Author/AS)

Four alternative theoretical models of intellectual competence were assessed, using confirmatory factor analysis to account for the correlation patterns derived from Wechsler intelligence tests. It was argued that the difference between the chi-square goodness of fit statistics that are provided when using confirmatory factor analysis gives a…

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)

Whether the one- or two-factor Wechsler or weighted sum scores (WSS) structural models adequately fit the Wechsler Intelligence Scale for Children III (WISC-III) covariance matrices was studied with samples of 2200 and 1118 children from previous studies. Both the WSS and supplemented models provided better fit than Wechsler's model but still…

The hypothesis that fluid intelligence is equivalent to the factor of general intelligence is investigated using LISREL to specify higher-order models in reanalyses of three sets of psychometric data from subjects 11, 13, and 15 years old. The three studies showed fluid intelligence to be equivalent with a general factor. (LMO)

Theoretical predictions, based on the confluence model, were made for data from six national surveys of intellectual performance, each relating intellectual performance scores to family configuration variables. The confluence model was capable of accurate prediction in all cases when three parameters were estimated. (Author/RD)

First- and second-round commentaries on an article by L. Guttman are presented. The following authors responded, with two articles each: (1) E. E. Roskam and J. Ellis; (2) P. H. Schonemann; (3) A. R. Jensen; (4) J. C. Loehlin; and (5) J.-E. Gustafsson. (SLD)

Longitudinal studies of personality traits and intelligence have used an exponential function to relate magnitudes of correlations between occasions to the time interval. This exponential function is shown to be equivalent to a quasisimplex model of a stationary process with constant reliability. (SLD)

After a brief review of the contributions of factor analysis and regional analysis to the elaboration of the structures of spatial abilities, a facet design and regional model for spatial abilities are presented. A cylindrical-wedge model is proposed to represent the correlational structure of spatial ability tests. (SLD)

By using complex multiple regression models to generate regression surfaces, the relationships between academic achievement, creativity, and intelligence are examined. Findings indicate that for certain academic subjects creativity is related to achievement up to a threshold level of intelligence, but after the threshold has been reached…

Structure of measures of speed was studied by conducting simultaneous confirmatory factor analysis for 1 sample of 149 elderly adults and a sample of 147 young adults using 16 measures of speed. Five first-order factors of speed were found, as hypothesized, and three second-order speed factors were necessary. (SLD)