Comparative validity of three Wechsler short forms for delinquents

Area of Science:

• Psychology
• Neuropsychology
• Forensic Psychology

Background:

• The Wechsler Intelligence Scales (WISC-R, WAIS, WAIS-R) are widely used for cognitive assessment.
• Short forms offer a time-efficient alternative for intelligence testing.
• The validity of short forms in clinical and forensic populations requires careful examination.

Purpose of the Study:

• To evaluate the validity of Vocabulary-Block Design short forms of the WISC-R, WAIS, and WAIS-R.
• To assess the utility of these short forms in a clinical population of male delinquents.

Main Methods:

• The study included 126 adjudicated male delinquents aged 16 years.
• Vocabulary-Block Design short forms were administered.
• Results were compared to full-scale IQ scores from the WISC-R, WAIS, and WAIS-R.

Main Results:

• Small, nonsignificant differences were found between short form and full-scale IQ means.
• Correlations between short forms and full-scale IQs ranged from .88 to .92, indicating substantial shared variance (77%-84%).
• The WAIS and WAIS-R short forms demonstrated superior classification accuracy compared to the WISC-R short form.

Conclusions:

• Wechsler short forms, particularly the WAIS and WAIS-R, are valid screening tools for assessing intelligence in older delinquents.
• These short forms are insufficient for making critical individual treatment program decisions.
• The findings support the use of specific Wechsler short forms as preliminary assessments in forensic settings.