Assessment of English- and Spanish-speaking students with the WISC-III and Leiter-R

The Leiter International Performance Scale-Revised (Leiter-R) and Wechsler Intelligence Scale for Children-Third Edition (WISC-III) scores of 47 English- and 47 Spanish-speaking students were analyzed, and the effects of English language ability on these scores were examined. Leiter-R validity was supported for both language groups. WISC-III validity was supported for English speakers but contained substantial construct irrelevant variance for Spanish speakers as a function of English proficiency as measured by the Woodcock Language Proficiency Battery-Revised Oral Language Scale (OLS). The WISC-III appeared to measure intelligence validly for Spanish speakers scoring ≥ 90 on the OLS but seemed to reflect linguistic ability for Spanish speakers scoring < 90. Because of similarities between the WISCIII and the newer WISC-IV index scores, the OLS criterion of ≥ 90 is suggested as a reasonable guideline for valid administration of the WISC-IV to Spanish speakers.