Studied age norms for 11 individual Wechsler Adult Intelligence Scale-Revised (WAIS-R) tests. Digit Symbol showed the most decline. Results suggest that fluid intelligence, as measured by the performance scale tests, shows more of a decline with age than crystallized intelligence, as measured by the verbal scale tests. (Author)

Validated models of mental addition processing by testing children and adults in a production task paradigm. Examined individual-difference relations between strategy choice parameters and criterion-related measures of ability. Found that individual differences in the apparently calculative processes that underlie numerical facility are highly…

Investigates (1) the relationships between cognitive performance and cognitive styles and predictive possibilities and (2) performance differences by sex, school, grade, and income in 92 Indian adolescents. Assessment measures included Liquid Conservation, Islands, Goat-Lion, Hanoi-Tower, Rabbits (Piagetian); Block Design (WISC-R); Paper Cutting…

The Conceptual Learning and Development (CLD) Model specifies four levels of concept attainment (concrete, identity, classificatory, and formal) and three uses of concepts (problem solving, subordinate-supraordinate, and principles). Longitudinal and cross-sectional studies of concept attainment may be conducted. The results of this study of 300…