Verbal-performance IQ discrepancies on the WAIS-R: estimated vs. empirical values

The accuracy of Payne and Jones's (1957) formula for evaluating the abnormality of test score differences was checked against the actual distribution of Verbal-Performance IQ discrepancies in the standardization sample for the Wechsler Adult Intelligence Scale-Revised. The results given by the formula appear sufficiently accurate for most clinical applications and support the formula's use when the actual distribution of differences is unknown.