Abstract

The short forms of the Wechsler Adult Intelligence Scale-Revised(Wechsler, 1981) have particular utility for individuals with schizophrenia because of their ability to provide estimated IQ scores with substantial time saving and, as a result, are less taxing for these patients who often show impaired attention and deficient motivation. Although valid short forms of the WAIS-R exist, they often require validation study. The purpose of this study is to compare the accuracy and validity of two short forms. The Korean-Wechsler Intelligence Scale(KWIS, 1963) was given to 105 schizophrenic patients, and IQs were estimated from Ward's seven subtests(Information, Arithmetic, Similarities, Digit Span, Digit Symbol, Picture Completion, Block Design) and Doppelt subtests (Vocabulary, Arithmetic), (Block Design, Picture Arrangement) that require about half the administration time of the full test. Results indicated that 86.7% of the estimated Full Scale IQs were ±5 points of their actual scores. Estimates correlated well with Verbal, Performance, and Full Scale IQs, and mean estimated IQs differed by less than 1 IQ point form actual means. Error sizes in predicting Full Scale Ids were small(M=2.43) and exceeded 6 IQ points in only 2 cases(1.9%). In comparison, error sizes for the Doppelt(1956) abbreviation(M=4.31) were significantly larger and were greater than 6 IQ points in 20 cases(19%). Furthermore, Ward's seven subtest short form had lower misclassification rate(9.5%) than Doppelt's subtest(35%). This abbreviated Wechsler Scale may be used with schizophrenic patients when only general estimates of intellectual functioning are required. However, all short forms had substantial misclassification rates, indicating that caution is warranted when using these forms to classify individuals according to standard levels of intellectual functioning. Finally, several limitations and suggestions of the present study were discussed.