Interrater reliabilities of the Adaptive Behavior Scale with environmental effects controlled.

Interrater reliabilities were obtained from 180 matched observers of adaptive behavior (using the Adaptive Behavior Scale) of mentally retarded adults. The study was designed to control for interactional differences in raters and administration method. There were no significant differences in reliability coefficients among informants using the three methods of administration. On Part One, domains describing skill acquisition and independent functioning were acceptably high. Domains of social-interactional skills were markedly lower. On Part Two, reliability coefficients were generally inconclusive, with the exception of acting out behavior that resulted in agreement among raters.