Abstract
One hundred and fifteen children with disabilities (42 with Down syndrome, 37 with motor impairment, and 36 with developmental delays) were observed in a total of 115 classrooms. Categories for coding children's behaviors in mastery tasks, social activities with peers, and compliance with teachers were recorded by trained observers, blind to the study hypotheses using a modified time sampling procedure. Composite scores representing (1) engagement and skill in completing mastery tasks, (2) engagement and skill in social interaction with peers, and (3) compliance with teachers were constructed from the observation categories. Hierarchical regression analyses indicated that specific classroom characteristics (i.e., class size, inclusiveness of class enrollment, teacher-child ratio, and percentage of time spent in one-on-one instruction) predicted performance on these behaviors above and beyond children's cognitive performance.