Two-and four-subtest short forms of the Wechsler Adult Intelligence Scale - revised : a comparative study with normals

Abstract

The concurrent validity of WAIS-R short forms was evaluated in a sample of normal subjects. The accuracy of short form IQ estimates from a standard administration was compared with the accuracy of an IQ estimate when the short form was administered first followed by the remaining subtests. Two-subtest short forms (Vocabulary/Block Design; Information/Picture Completion) and four-subtest short forms (Arithmetic/ Similarities/Picture Completion/Digit Symbol; Vocabulary/Block Design/Arithmetic/Picture Arrangement) were examined. It was found that the performance of the four-subtest short forms was comparable in both administrative conditions. The Vocabulary/Block Design short form was a good estimate of full scale IQ when administered first and overestimated full scale IQ when rescored. The role of motivational factors in short form estimates is discussed. The Information/Picture Completion short form had low validity. The results support clinicians' continued caution in the use of short forms. More research utilizing the methodology of this study is recommended when evaluating short form validity.