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 | ||
| Verbal ability | |||
| Non-verbal/performance 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) |
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| 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.
Go to:
- 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’.