The Avon Longitudinal Study of Parents and Children (ALSPAC) assessed their cohort members (CMs) during the study’s age 8.5 sweep (Focus@8) using the Wechsler Intelligence Scale for Children (WISC-III).
Details on this measure and the data collected from the CMs are outlined in the table below.
|Domain:||Verbal and non-verbal ability|
|Measures:||General cognitive ability|
|CHC:||G (General ability)|
|Administration method:||Trained interviewer; clinical setting|
|Procedure:||The WISC-III is a measure of cognitive functioning designed for children aged 6-17 years. It is comprised of two scales, verbal and performance (non-verbal), and each of these scales contains 5 subtests. The verbal subtests are: i) vocabulary, ii) similarities, iii) arithmetic, iv) information, v) comprehension. The performance subtests are: i) object assembly, ii) coding, iii) block design, iv) picture arrangement, v) picture completion. Each subtest is described individually in the sections below. A short-form measure of the WISC was administered to reduce burden/fatigue on the children (with the exception of the coding test which was administered in full). Scores from this short-form version can be transformed to approximate scores on the full version as follows; multiplying by 2 scores for picture completion, information, arithmetic, vocabulary, comprehension and picture arrangement; multiplying by 5/3 for similarities; and multiplying by 3/2 for object assembly and block design. The WISC-III provides standard scores (M = 100, SD = 15), on verbal IQ, performance IQ and fullscale IQ. Scores on the individual subtests are standardised (M = 10, SD = 3). Raw scores are converted into scale scores using tables provided in the WISC-III manual. If fewer than 3 subtests were completed by the child, verbal, performance and fullscale IQ were not computed for that child. If 4 out of 5 subscales were completed on the verbal/performance scales, the mean of the 4 scales was substituted in for the missing 5th. This prorating strategy is a standard practice when using WISC-III.|
|Link to questionnaire:||http://www.bristol.ac.uk/alspac/researchers/our-data/clinical-measures/ (opens in new tab)|
|Scoring:||Standardised score (M = 100, SD = 15)|
|Item-level variable(s):||Not readily available|
|Total score/derived variable(s):||f8ws020 - f8ws155|
|Descriptives:||Total IQ||Verbal IQ||Performance IQ|
|N = 7,348||N = 7,379||N = 7,371|
|Range = 45 - 151||Range = 46 - 155||Range = 46 - 151|
|Mean = 103.97||Mean = 106.95||Mean = 99.46|
|SD = 16.53||SD = 16.79||SD = 17.12|
|(click image to enlarge)||(click image to enlarge)||(click link to enlarge)
|Age of participants:||Mean = 103.82 months, SD = 3.92, Range = 89 - 127|
|Other sweep and/or cohort:||None|
|Source:||Wechsler, D. (1991). WISC-III: Wechsler intelligence scale for children: Manual. Psychological Corporation.|
|Technical resources:||Kaufman, A. S., & Lichtenberger, E. O. (2000). Essentials of WISC-III and WPPSI-R assessment. John Wiley & Sons Inc.|
|Reference examples:||Northstone, K., Joinson, C., Emmett, P., Ness, A., & Paus, T. (2012). Are dietary patterns in childhood associated with IQ at 8 years of age? A population-based cohort study. Journal of Epidemiology and Community Health, 66(7), 624-628.|
|Bornstein, M. H., Hahn, C. S., & Wolke, D. (2013). Systems and cascades in cognitive development and academic achievement. Child Development, 84(1), 154-162.|
For the named items in the table above, links are provided to their corresponding content on CLOSER Discovery. Where a variable range is provided, full variable lists can be accessed through the ‘Variable Groups’ tab on the linked Discovery page.
- Overview of all cognitive measures in ALSPAC
- Overview of childhood cognitive measures across all studies
This page is part of CLOSER’s ‘A guide to the cognitive measures in five British birth cohort studies’.