The Adaptive Behavior Scale, as developed, contains 10 domains of behavior reflecting independent functioning and social-emotional responsibility in Part One, and 14 domains of behavior appraising social-emotional adaptation in Part Two. The establishment of construct validity and standardization of the Scale for use with normal and handicapped students attending public school is described in terms of several studies, using class placement as the adaptive behavior criterion, to which multiple regression and multivariate analysis of variance procedures have been applied. The following areas of concern are addressed by the validity studies: (1) use of the Scale to measure a wide range of levels of adaptive behavior of normal and handicapped children; (2) identification of mildly retarded students by the Scale's measurement of different types of social functioning; (3) the ability of the Scale to provide an individual profile which can be used to plan and develop an appropriate educational program for the pupil; and (4) the general applicability of the Scale as a tool for educational diagnosis. (Author/HLM)