Independent Behavior, and the AAMR Adaptive Behavior Scale-School Edition (Stinnett et al., 1994). The Adaptive Behavior Assessment System (Harrison & Oakland, 2000a) is quite new and relatively untested, but its psychometric properties and norms extend to age 89.

Each of these scales (except the Adaptive Behavior Assessment System) has been reviewed extensively and compared with others in detailed reports. Readers are referred to the test manuals and to Reschly (1990), Harrison and Robinson (1995), Thompson et al. (1999), Jacobson and Mulick (1996), Spector (1999), Hill (1999), Test Critiques, test reviews in the Journal of Psychoeducational Assessment, and the Mental Measurements Yearbooks for more detailed psychometric information about these and other measures. Although each scale described has both strengths and weaknesses, each has impressive psychometric characteristics and is highly recommended for use in eligibility determination and diagnosis. Decisions about which instrument to use depend on the age of the individual to be tested and available norms, available sources of information, the context in which the individual is known, and the training of the rater.

The Vineland Adaptive Behavior Scales (VABS—Sparrow et al., 1984a) have their conceptual roots in the Vineland Social Maturity Scale (Doll, 1936b), although overlap between the original and the new scales is minimal (Kamphaus, 1987b). There are actually three scales, including a survey form (VABS-S) and an expanded form (VABS-E), which uses a conversation data gathering format during interviews with parents or guardians. A psychologist, social worker, or other professional who has appropriate training in interview techniques must complete these forms. Norms on children having no disability are available from birth to 18 years, 11 months, based on a standardization sample of 3,000 cases that were stratified by age, gender, ethnicity, parental education, geographic region, and community size consistent with U.S. census data. The proportion of children from homes with low socioeconomic status was lower than that in the cen-