Applied reliable component analysis (RCA) to the normative data (2,100 children and adolescents) for the Universal Nonverbal Intelligence Test (UNIT) (A. Bracken and R. McCallum, 1998) to allow for the computation of reliable uncorrelated memory and reasoning scores. RCA sores were highly replicable, had good convergent validity, and had greater…

In this study, cognitive processes hypothesized to be relevant to the digit symbol task of the Wechsler Adult Intelligence Scale (WAIS) were examined. Fifty-two undergraduate education students were divided into four groups to receive four different treatments. All the students took the digit symbol test, followed immediately by a test of their…

The two-level theory of mental abilities posits two broad classes of ability: level I (learning and memory) and level II (the "g" factor of intelligence tests, reasoning, abstraction, and problem solving). Levels I and II are hypothesized to interact with SES and/or race such that: (l) SES differences are greater for level II than for I,…

The purpose of this study was to attempt to determine if score gains obtained upon repeated testing with an intelligence test result from a practice effect, from students remembering specific items, or from a combination of both. The verbal and nonverbal batteries of an I.Q. test were administered to 860 sixth graders on three occasions with…