Intra-individual subtest variability on the Dutch Wechsler Intelligence Scales for Children-Revised (WISC-R(NL)) for children with learning disabilities, psychiatric disorders, and epilepsy.
It is common practice to look at disparities among subtest scores ("scatter") on an intelligence test to establish if a score is deviant. However, it remains unclear whether subtest scatter reflects primarily normal variation within individuals or is clinically meaningful. The present study explored this issue based on data from 467 children with developmental disabilities tested on the Dutch WISC-R(NL). Of these children, 132 had learning disabilities, 178 had psychiatric disorders, and 157 had epilepsy. Subtest scatter was defined as scaled-score range (highest minus lowest scaled score). When contrasted with "normal scatter," the overall sample revealed higher ranges on the Performance Scale and Full Scale, although effect sizes were small. Analysis of the data for the three separate clinical samples revealed unusual scatter only for the sample of children with psychiatric disorders. When comparing the clinical samples, scaled-score range was larger for the sample of children with psychiatric disorders than for those with epilepsy. Two distinct subsamples revealed elevated ranges with moderate effect sizes: children with autistic spectrum disorders and children with left hemisphere seizures. These results suggest that elevated subtest scaled-score range might characterize specific clinical samples rather than denoting an overall sign of pathology.
SEIN, Stichting Epilepsie Instellingen Nederland, Afdeling Psychologie, Postbus 21, 2100 AA Heemstede, The Netherlands. lviterson@sein.nl
Loretta
L
van Iterson
Alan S
AS
Kaufman
D000293:Adolescent; D002648:Child; D015897:Comorbidity; D003431:Cross-Cultural Comparison; D004519:Education, Special; D004827:Epilepsy / Q000523:psychology*; D005260:Female; D006801:Humans; D007206:Individuality; D007859:Learning Disabilities / Q000175:diagnosis* / Q000523:psychology; D008297:Male; D001523:Mental Disorders / Q000175:diagnosis* / Q000523:psychology; D009426:Netherlands; D011594:Psychometrics; D012016:Reference Values; D015203:Reproducibility of Results; D014888:Wechsler Scales / Q000706:statistics & numerical data*