Speed of information processing: A third factor of the WISC-R

Abstract

The role of response time on the Wechsler Intelligence Scale for Children-Revised (WISC-R) was investigated. The complete WISC-R was administered to 131 children. A total response time (TRT) score for correct and incorrect performance was gleaned from each of the Picture Arrangement (PATRT), Block Design (BDTRT), and Object Assembly (OATRT) subtests. The utility of these response time measures was examined in relation to other WISC-R subtests. A principal factors analysis of the above data revealed that the three response time measures loaded on factors that were independent of the WISC-R subtests. However, a subsequent principal components factor analysis using orthogonal rotations produced three factors with eigenvalues greater than 1.0. Factors 1 and 2 accounted for 41.9% and 15.1% of the variability and were explained, respectively, by loadings from the Verbal and Performance scale subtests. Interestingly, only the three response time measures significantly loaded on the third factor, which accounted for 7.9% of the variability. The relationship between intelligence and the speed of information processing, as presented by the response measures, is discussed.