Incremental Efficacy of Differential Ability Scales Factor Scores in Predicting Individual Achievement Criteria.

Examines the incremental validity of Differential Ability Scales (DAS) factor scores in predicting standardized achievement scores in Word Reading, Basic Number Skills, and Spelling by using a nationally representative sample stratified on gender, ethnicity, geographic region, parental education, and educational classification. Results show that improvement was consistently too small in size to be of clinical significance. (Author/JDM)