Data collection can be the most time- and cost-intensive part of developmental research. This article describes some long-proposed but little-used research designs that have the potential to maximize data quality (reliability and validity) while minimizing research cost. In "planned missing data designs", missing data are used…

Because of the Flynn effect, IQ scores rise as a test norm ages but drop on the introduction of a newly revised test norm. The purpose of the current study was to determine the impact of the Flynn effect on learning disability (LD) diagnoses, the most prevalent special education diagnosis in the United States. Using a longitudinal sample of 875…

Following the ongoing increase in nonmarital fertility, policy makers have looked for ways to limit the disadvantages faced by children of unmarried mothers. Recent initiatives included marriage promotion and welfare-to-work programs. Yet policy might also consider the promotion of three generational households. We know little about whether…

The mental growth patterns of 204 children were investigated on four different test occasions covering a five-year period, ages six to 11. There is no evidence of intellectual differentiation after age six nor is there a systematic decline in size of WISC subtest intercorrelations with increasing age. (Authors)

The long term predictive validity of the Wechsler Intelligence Scale for Children (WISC) and the Bender Visual Motor Gestalt Test for Children, when used for the educational placement of exceptional students, was investigated. In 1971, 225 learning disabled elementary school students were tested on the WISC and the Bender. The students were…