Stability of WISC-R scores in a juvenile forensic sample.

The temporal stability of WISC-R IQ Scale and subtest scores was examined in a Juvenile Court sample comprised primarily of neglected youth (N = 36). Stability coefficients were calculated for an average test-retest span of more than 2 years. WISC-R IQ Scale subtest scores were found to be stable to a degree comparable with WISC-R standardization data despite the considerably longer test-retest interval. Stability coefficients were .88 for Verbal IQ, .86 for Performance IQ, and .93 for Full Scale IQ. Subtest stability coefficients range from .49 to .82; many coefficients are equal to or greater than .70. No practice effects were apparent.