The effectiveness of the special school, special class, and regular class in the education of low IQ (49 to 70) and high IQ (71 to 85) educable mentally retarded pupils (n=120) (all between the ages of 7 and 12 years) was investigated. Effectiveness was determined by academic achievement, self concept, and social adjustment within school settings and social adjustment in community settings over 2 years. The Wide Range Achievement Test, the Piers Harris Self Concept Scale, and an investigator adapted sociometric test were used to assess these factors. Three randomly selected groups of 30 pupils from each group (special school, special class, and regular class) in the school and 10 pupils from each group in the community were studied. Results indicated that there were no significant differences among total groups with the three administrative settings in reading, spelling, or arithmetic; that there were significant differences on some measures of academic achievement when groups were divided in terms of high and low IQ; that there were no significant differences found in self concept among total groups of high IQ groups; that both total groups of pupils and low IQ pupils were significantly better adjusted socially in the special school and special class than in the regular class; and there were no significant differences in the social adjustment of high IQ pupils among the three administrative groups. (Author/SB)