An evaluation instrument (BRIAAC) for assessing untestable children is described. The observational tool is said to be particularly appropriate for autistic and other severely withdrawn children. The BRIAAC assesses level of present function and measures behavior changes in the following areas: relationship with an adult (physically and emotionally), communication with peers and adults, drive for mastery, vocalization and expressive speech, sound and speech reception, social responsiveness, body movement, and psychobiological development (from primitive to later personality characteristics). Scoring procedures are described. (CL)