Various experiments demonstrated that the difficulty level of several performance-type intelligence test tasks is determined directly by stimulus and task variables that vary the information to be processed. The implications of these findings for intelligence and the problems of an experimental approach to the measurement of intelligence are…

First, third, fifth and eleventh graders were videotaped as they completed the Block Design Subtest of the WISC-R. Neither the order of placement of blocks within each design nor the degree to which children persisted in placing a given block correctly before moving to the next one evidenced developmental differences. (Author/RD)

Eight-seven adult outpatients in Edinburgh (Scotland) were tested with the Wechsler Adult Intelligence Scale--Revised (WAIS-R) and a test of visual inspection time (IT). Factor analysis confirms that IT correlates more strongly with performance than with verbal intelligence quotient (IQ) scores. Implications for the study of IT and mental tests…

Results from a representative sample of 123 adults in the United Kingdom tested with the Wechsler Adult Intelligence Scale-Revised and a test of word identification time are in line with previous findings that speed of information processing is significantly related to performance IQ but not to verbal IQ. (SLD)

Items showing sex differences on the revised Wechsler Adult Intelligence Scale (WAIS-R) were studied. In a sample of 206 young adults (110 males and 96 females), 15 items demonstrated significant sex differences, but there was no relationship of item-specific gender content to sex differences in item performance. (SLD)

Three forms of a symbol-digit substitution task were administered to 62 female and 96 male college students. Results support the theory that the superior performance of women over men on the Digit-Symbol Substituion subtest of the Wechsler scales is due to their greater ability to encode symbols verbally. (Author/JAC)