This study investigated time allocated to instruction as a function of the specific type of mild handicap and as a function of setting and subject matter content. Subjects were 122 elementary students categorized as learning-disabled, emotionally/behaviorally disturbed, educable mentally retarded, and nonhandicapped. Subjects were in mainstreamed, resource room, and self-contained programs. A modified version of the CISSAR (Code for Instructional Structure and Student Academic Response) observation system was used. Twelve specific activities were coded (8 academic; 4 nonacademic); activities were coded every 10 seconds; and each student was observed on a whole-day basis. Results showed that few significant differences existed among the student categories in the amount of time allocated to various activities--the act of differential classification did not result in quantitative differences in the ways in which students spent their time in school. Compared to time spent in regular classes, a greater proportion of the time that students spent in special education classes was allocated to academic instruction. Mentally retarded students in self-contained classes spent significantly less time on academic instruction than mentally retarded students in resource rooms or regular education classes. (JDD)