Traditional Psychometric Tests and Proportionate Representation: An Intervention and Program Evaluation Study

The Wechsler Intelligence Scale for Children-Revised (WISC-R) and Standard Raven Progressive Matrices (SPM) Test were evaluated in the context of an intervention/program evaluation study and in terms of a proportionate representation model of test bias. A total of 26,300 boys and girls from 8 different ethnic backgrounds were evaluated over a 9-year period. An intervention based on monitoring of and feedback to referral sources proved effective in improving proportionate representation in the referral process. Moreover, the WISC-R and SPM showed approximately equal predictive validity and no evidence of differential validity. Significant differences were found as a function of ethnic background between those referred and those certified as gifted, as well as between those referred and those who scored in the 98th percentile on either test. Implications for traditional tests are discussed.