The study examines the extent to which categorical differences exist in the qualitative nature of instruction for mildly handicapped students. Interviews and observations were conducted of 30 learning disabled (LD), 32 emotionally-behaviorally disturbed (EBD), and 30 educable mentally retarded (EMR) students in grades 2-4. Instruction was evaluated in terms of six instructional clusters based on principles of effective instruction: (1) instructional planning, (2) instructional presentation, (3) checking for student understanding, (4) task relevance, (5) practice, and (6) feedback. In general, the average ratings on the instructional clusters were high for all groups. Quality of instruction was very similar for LD and EBD groups. Instruction of EMR students, however, was rated lower on checking for student understanding, instructional presentation, and task relevance. The study raises questions concerning the value of classifying students and suggests more emphasis on monitoring the effectiveness of instruction for each student's progress. (DB)