A sample suffers range restriction (RR) when its variance is reduced comparing with its population variance and, in turn, it fails representing such population. If the RR occurs over the latent factor, not directly over the observed variable, the researcher deals with an indirect RR, common when using convenience samples. This work explores how…

Advancements in item response theory (IRT) have led to models for dual dependence, which control for cluster and method effects during a psychometric analysis. Currently, however, this class of models does not include one that controls for when the method effects stem from two method sources in which one source functions differently across the…

The six California Achievement Tests (CAT) subtests were factor analyzed separately for Black males, Black females, Hispanic males, Hispanic females, White males, and White females, in the fifth and seventh grades. the CAT was found to be essentially invariant with regard to race and sex. (Author/BS)