WIAT SUBTEST AND COMPOSITE PREDICTED-ACHIEVEMENT VALUES BASED ON WISC-III VERBAL AND PERFORMANCE IQS

Critical values tables for determining significant differences between Wechsler IQs and WIAT subtests and composites based on a predicted-ac hievement method are provided in the WIAT manual for the Full Scale IQ and have been constructed recently for Verbal and Performance IQs (Fl anagan & Alfonso, 1993). In order to use these tables, however, a pred icted achievement score(s) is required. The process of calculating pre dicted-achievement scores is time-consuming and may result in errors, especially when more than one ability-achievement comparison is warran ted. The present paper provides tables of WIAT subtest and composite p redicted-achievement standard scores based on WISC-III Verbal and Perf ormance IQs. These tables allow examiners to determine quickly ability -achievement discrepancies based on WISC-III Verbal or Performance IQs when they are used in conjunction with the critical values tables pro vided in our earlier article. These tables are most useful for the acc urate assessment and diagnosis of learning disabilities.