SPEECH IMPROVEMENT TECHNIQUES FOR MENTAL RETARDATES WERE EXAMINED USING COMMUNICATION-CENTERED SPEECH THERAPY TO ENHANCE ARTICULATION AND GENERAL ORAL PRODUCTION AND TO IMPROVE SUCH RELATIONSHIP ATTRIBUTES AS COMMUNICATIVE INITIATIVE AND EASE IN SOCIAL SITUATIONS. A BATTERY OF TEST DEVICES WAS DEVELOPED, INCLUDING THE SAN FRANCISCO INVENTORY OF COMMUNICATIVE EFFECTIVENESS (SFICE) WHICH USES A COMMUNICATIVE ATTRIBUTES RATING SCALE AND A VERBAL OUTPUT SCALE, AN ARTICULATION PROFILE, AND A SOUND DISCRIMINATION TEST. TWO TYPES OF SPEECH TRAINING WERE USED IN THE STUDY--CONVENTIONAL THERAPY AND COMMUNICATION-CENTERED THERAPY. TESTS WERE ADMINISTERED TO EXPERIMENTAL SUBJECTS PRIOR TO AND AFTER THERAPY AND TO CONTROL SUBJECTS WHO RECEIVED NO THERAPY. CLINICAL EXPERIENCE GAINED DURING THE PROGRAM INDICATED THE EFFECTIVENESS OF COMMUNICATION-CENTERED SPEECH THERAPY, USING APPROACHES DUPLICATING REAL-LIFE EXPERIENCES RATHER THAN A DRILL-TYPE INSTRUCTIONAL APPROACH. HOWEVER, SINCE THIS STUDY WAS NOT DESIGNED TO SPECIFY AND TEST INDIVIDUAL PRINCIPLES AND TECHNIQUES OF COMMUNICATION-CENTERED SPEECH THERAPY, FURTHER STUDY OF THIS APPROACH IS RECOMMENDED IN WHICH ITS SPECIFIC FEATURES WILL BE MORE THOROUGHLY APPRAISED. (JH)