Haddad F A, Juliano J M, Vaughan D
Arizona State University.
Psychol Rep. 1994 Feb;74(1):15-8. doi: 10.2466/pr0.1994.74.1.15.
Stability of IQ for race and gender was examined by analyzing the results of two administrations over 3 years of the WISC-R for 402 learning disabled children. About 50% of the variance in Test 2 was accounted for by scores on Test 1. Frequency of positive or negative difference for each IQ from Test 1 to Test 2 was presented. Direction of change in IQ was negative for the Verbal Scale and positive for changes on the Performance Scale.
