This study aims to evaluate the criterion-related validity of K-WAIS-Ⅳ by verifying if K-WAIS-Ⅳ and K-WAIS intelligence quotients are identical. Accordingly, this study uses Korean Wechsler Adult Intelligence Scale by differing the order of applic...
This study aims to evaluate the criterion-related validity of K-WAIS-Ⅳ by verifying if K-WAIS-Ⅳ and K-WAIS intelligence quotients are identical. Accordingly, this study uses Korean Wechsler Adult Intelligence Scale by differing the order of application to normal male and female adults whose academic ability is college graduate or higher in their 20s (Group 1: K-WAIS-Ⅳ first, Group 2: K-WAIS first). As a result of correlation analysis and difference verification in subtests which are common between K-WAIS-Ⅳ and K-WAIS, it is found that in considerable subtests common between K-WAIS-Ⅳ and K-WAIS, they are related each other and K-WAIS-Ⅳ VCI (Verbal Comprehension Index) represents K-WAIS VIQ (Verbal IQ) and K-WAIS-Ⅳ PRI (Perceptual Reasoning Index) represents K-WAIS PIQ (Performance IQ). Furthermore, in considerable subtests of K-WAIS-Ⅳ (Block Design, Similarity, Digit Span, and Coding), Flynn effect that indicated an increase in old version of intelligence quotients appeared, but in case of Information subtests, rather a reduction in old version of IQ, in other words, a reversal of Flynn effect was observed, which suggests that in Korea, it is likely to have a reversal of Flynn effect which is observed in advanced countries.
At the same time, K-WAIS-Ⅳ PSI (Processing Speed Index) had a value as independent index and there was a statistically significant difference in age-specific converted scores between K-WAIS-Ⅳ Coding and K-WAIS Digit Symbol. The effect size (Cohen’s d) also appeared at the highest level. Like this, as a result of analyzing the causes why there was an excessive score difference in Coding subtests, it is found that there was an evidence showing that difficulty in K-WAIS-Ⅳ Coding became higher, which might have caused confusion in converted score manufacturing process. Therefore, this study suggests the necessity of additional tests to measure the processing speed ability in examinees who showed noticeable difference in scores more than 1 standard deviations in Coding subtests which belong to PSI among highly educated persons in their 20s in the process that practitioners are conducting K-WAIS-Ⅳ.