A Comparison of the WISC-III and the Otis-Lennon School Ability Test with Students Referred for Learning Disabilities

Abstract

The Otis-Lennon School Ability Test-Sixth Edition (OLSAT-6) and the Wechsler Intelligence Scale for Children-Third Edition (WISC-I1) were administered to 201 elementary school children who were referred for evaluation of possible learning disabilities. The OLSAT-6 and the WISC-III were significantly correlated (r = .62, r2 = 38%), although the WISC-III Full Scale IQs were significantly higher than the OLSAT-6 Total scores. In two-thirds of cases, the OLSAT-6 Total score underestimated the WISC-III Full Scale IQ by a range of 1 to 35 points. The standard error of estimate for the OLSAT-6 in predicting the WISC-III was 7.48 points. The use of the OLSAT-6 in estimating overall intellectual abilities in children with suspected learning disabilities is not encouraged because it may frequently underestimate students' actual abilities, which may result in fewer appropriate referrals for further educational and intellectual assessment.