AN EXPERIMENTAL PROGRAM FOR EDUCABLE RETARDATES, AGES 4 TO 6 YEARS, WAS CONDUCTED TO STUDY THE EFFECTS OF PLANNED GROUP PARTICIPATION UPON INDIVIDUAL ADJUSTMENT, STRUCTURED TRAINING PROGRAMS UPON INDIVIDUAL LEARNING, THE PRECEDING TWO ACTIVITIES UPON LATER SCHOOL ADJUSTMENTS AND LEARNINGS, AND PARENTAL ATTITUDES UPON OVERALL CHILD DEVELOPMENT. THE OBJECTIVES OF THE PROGRAM WERE TO PRODUCE INFORMATION RELATING TO THE DEVELOPMENT OF TEACHING METHODS AND MATERIALS, HYPOTHESES REGARDING PATTERNS OF ACADEMIC GROWTH AND SOCIAL ACHIEVEMENTS, AND RECOMMENDATIONS FOR FURTHER RESEARCH IN PRESCHOOL EDUCATION FOR THE MENTALLY RETARDED. CHILDREN WERE DIVIDED INTO EXPERIMENTAL AND CONTROL GROUPS, AND STATISTICAL DATA WERE OBTAINED FROM A CROSS-SECTIONAL, LONGITUDINAL MATRIX OF PHYSICAL EXAMINATIONS, SOCIAL CASE WORK, SPEECH AND DRAWING RECORDS, AND OTHER CLASSROOM REPORTS AND OBSERVATIONS. EARLY IDENTIFICATION TECHNIQUES, PRESERVICE AND INSERVICE EDUCATIONAL PROGRAMS, UNDERSTANDINGS OF SOCIOECONOMIC AND MEDICAL BACKGROUNDS, AND TESTING RESEARCH ARE DISCUSSED IN SUMMARIES OF PROJECT IMPLICATIONS AND RECOMMENDATIONS. (JH)