The Relationship Between the Kaufman Brief Intelligence Test (K-Bit) and the Wechsler Intelligence Scale for Children-Iii (Wisc-Iii) with Adolescent Psychiatric Inpatients

Intelligence has been of interest to psychologists for decades. There are many comprehensive measures of intelligence. However, the lengthy administration times of such tests often preclude their usefulness in many circumstances. There have been several attempts to develop brief measures of intelligence. One of the most recently developed measures is the Kaufman Brief Intelligence Test (K-BIT) (Kaufman & Kaufman, 1990). This test has proven to be a valid and effective screening measure for the Wechsler Intelligence Scale for Children-Revised (WISC-R) (Wechsler, 1974), when used with juvenile delinquents and students referred for academic difficulties. There have been no studies to date that examine the relationship between the KBIT and the WISC-III, the most recent revision of the Wechsler scales. The primary purpose of this study was to examine the relationship between the K-BIT and the WISC-III when used with adolescent psychiatric inpatients. Data obtained from psychological evaluation records of adolescents admitted to Osawatomie State Hospital were analyzed. Comparisons were made between scores obtained by these adolescents on the K-BIT and on the WISC-III. These comparisons were carried out to determine if the K-BIT could be used, with adolescent psychiatric inpatients, to provide preliminary information regarding intellectual ability until the WISC-III could be administered. Pearson product-moment correlations showed strong significant relationships between the K-BIT and WISC-III the scores of the verbal, nonverbal and overall measures, suggesting that these two instruments measure similar constructs. However, three paired t-tests resulted in mean verbal, nonverbal, and overall scores on the K-BIT that were significantly higher than mean verbal, nonverbal, and overall scores on the WISCIII. This demonstrates that the K-BIT overestimates intellectual ability when the WISC-III is the follow-up or comprehensive measure of intelligence. Two single-sample t-tests showed that the adolescent psychiatric inpatients obtained mean overall scores that were significantly lower than the normal control subjects used in the standardization samples of these two instruments. The implications of these results, with respect to treatment, are discussed