AN EVALUATION AND OBJECTIVE COMPARISON WAS MADE BETWEEN THE PROGRESS OF YOUNG MENTAL RETARDATES IN REGULAR CLASSROOMS WITH THE PROGRESS OF PEERS IN SPECIAL CLASSES. THE BASIS OF COMPARISON OF THE TWO TEACHING METHODS INCLUDED MENTAL DEVELOPMENT, PROGRESS IN REGULAR SCHOOL SUBJECTS, ACHIEVEMENT TOWARD OTHER EDUCATIONAL GOALS, SOCIAL ADJUSTMENT INSIDE AND OUTSIDE THE CLASSROOM, AND PHYSICAL GROWTH AND COORDINATION. THESE PROBLEMS WERE STUDIED IN A LARGE NUMBER OF DIFFERENT SCHOOL ENVIRONMENTS, INCLUDING RURAL SCHOOLS AND LARGE AND SMALL CITY SCHOOL UNITS. WHEN THE STUDY WAS CONCLUDED AND ALL DATA WERE ANALYZED, OVERALL SOCIAL AND PHYSICAL PROGRESS SEEMED TO FAVOR THE SPECIAL CLASSES. HOWEVER, THE RESULTS SHOWED THAT THE SUBJECTS DID BETTER ACADEMIC WORK IN A REGULAR CLASSROOM THAN THOSE WHO WERE PLACED IN A SPECIAL CLASS. EXPLANATIONS FOR THIS FACT ARE OFFERED. (JH)