Validity and Reliability Evidence for the Comprehensive Test of Nonverbal Intelligence–Second Edition Scores From an Independent Sample

In this study, we examined the factor structure, reliability, and external validity of scores from the Comprehensive Test of Nonverbal Intelligence–Second Edition (CTONI-2) using an independent sample of young adults currently enrolled in a postsecondary institution. Although the subtests appear to be measuring general intelligence, the aggregate Full Scale score should be interpreted with caution when using the instrument with adults suspected of having above average intelligence. The item difficulties were too low to capture individual differences in adults with higher intelligence. Moreover, the scores’ reliability and the relations to measures of academic achievement are lower than what is typically expected for intelligence measures