The Stanford Binet fourth edition and its use with individuals with Down syndrome: Cautions for clinicians

Stanford Binet: Fourth Edition (SB:IV) assessments have been collected longitudinally for 195 individuals with Down syndrome. This article discusses individual assessments which were selected for their ability to highlight major concerns that practitioners need to consider when interpreting intelligence test scores with this population. In this study, Intelligence Quotient (IQ) changed substantially for many individuals, demonstrating changes in classification from a mild level of intellectual impairment on initial assessment to a severe level on later assessment. Subtests used in calculating composite scores were found to have a dramatic effect on IQ. There was up to 9 IQ points difference depending on whether only the “core” subtests or all subtests used by the assessor were included in the calculations. Thirty-seven percent of the assessments were at “floor level” (i.e., IQ of 36), despite obvious divergent abilities illustrated by age equivalent scores. Mean Age Equivalent (MAE) scores were also problematic as they failed to adequately represent either the range, or divergence, of abilities of the individuals whose data are presented. Directions for future research are discussed.