An intelligence test, first published in 1979, designed for use with children and adolescents up to 17 or 18 years of age, comprising a set of 23 subtests designed to measure a wide diversity of mental abilities and yielding three scores: visual IQ, verbal IQ, and general IQ. Its subtests are designed to measure the following six mental processes: speed of information-processing, reasoning, spatial imagery, perceptual matching, short-term memory, and retrieval and application of knowledge. The correlations between the subtests are all moderate or high, and general IQ scores derived from the test correlate well with independent measures of scholastic and academic attainment. See also Rasch scale. BAS abbrev.