Mw. Watkins et Fc. Worrell, Diagnostic utility of the number of WISC-III subtests deviating from mean performance among students with learning disabilities, PSYCHOL SCH, 37(4), 2000, pp. 303-309
This paper examined the diagnostic utility of subtest variability, as repre
sented by the number of subtests that deviate from examinees' mean IQ score
s, for identifying students with a learning disability (LD). Participants c
onsisted of the 2,200 students in the WISC-III normative sample and 684 stu
dents (Mdn grade = 5: M age = 10.8) identified as LD. The number of subtest
s deviating from examinees' Verbal, Performance, and Full Scale IQ by +/-3
points for normative and exceptional samples were contrasted via Receiver O
perating Curve (ROC) analyses. Results indicated that LD students did not d
iffer from normative sample children at levels above chance. It was conclud
ed that deviation of individual subtest scores from mean IQ scores has no d
iagnostic utility for hypothesizing about students with learning disabiliti
es. (C) 2000 John Wiley & Sons, Inc.