Gifted Issues Discussion homepage Forums Identification, Testing & Assessment Group ability tests vs. IQ tests

The entire cohort of grade 3 students in a Canadian urban school board was screened in the school years 1991-1992,1992-1993 and 1993-1994 to identify gifted students. All 2,306 students look the Otis-Lennon School Abilities Test-6th Edition (OLSAT-6), after which 261 students also took the Wechsler Intelligence Scale for Children-3rd Edition (WISC-III). Based on the WISC-III scores, 2.3% of the population were identified as gifted at the 98th percentile or higher, whereas 2.6% scored at the 97th percentile or higher and 3.7% at the 96th percentile or higher. An equivalent number of boys and girls were identified as gifted with WISC-III. In contrast, using the OLSAT-6 alone, only 1.2% of the population would be identified as gifted at the 98th percentile or higher, 1.7% would be identified at the 97th percentile or higher, and 2.2% would be identified at the 96th percentile or higher. The correlation between WISC-III and OLSAT-6 for students scoring at the 98th percentile or higher on the WISC-III was .39 in this small sample of students having a restricted range of scores on both tests. Discrepancies between WISC-III Verbal and Performance IQ scores and between OLSAT-6 Verbal and Nonverbal Scaled Scores for gifted students are presented. When used alone, the OLSAT-6 does not appear to be an effective screener for grade 3 students who will score in the gifted range on WISC-III.

In this study, the authors compare the validity of three nonverbal tests for the purpose of identifying academically gifted English-language learners (ELLs). Participants were 1,198 elementary children (approximately 40% ELLs). All were administered the Raven Standard Progressive Matrices (Raven), the Naglieri Nonverbal Ability Test (NNAT), and Form 6 of the Cognitive Abilities Test (CogAT). Results show that the U.S. national norms for the Raven substantially overestimate the number of high-scoring children; that because of errors in norming, the NNAT overestimates the number of both high-scoring and low-scoring children; that primary-level ELL children score especially poorly on the NNAT; that the standard error of measurement was twice as large for the NNAT as for the Raven or the CogAT; that ELL children scored .5 to .67 standard deviations lower than non-ELL children on the three nonverbal tests; and that none of the nonverbal tests predict achievement for ELL students very well.