THIS PROJECT WAS DESIGNED TO INCREASE PARENT PARTICIPATION IN THE VOCATIONAL REHABILITATION OF ADOLESCENT AND YOUNG ADULT MENTALLY HANDICAPPED PERSONS, TO DEVELOP METHODS OF MOTIVATING PARENTS TO PARTICIPATE, AND TO INVESTIGATE THE RELATIONSHIP BETWEEN PARENT PARTICIPATION AND THE RETARDATE'S VOCATIONAL ADJUSTMENT. DURING THE FIRST YEAR, EXPERIMENTAL AND CONTROL GROUPS OF 78 PARENTS EACH WERE SELECTED AND RANDOMLY ASSIGNED TO SUBGROUPS BASED ON THE VOCATIONAL PLACEMENT OF THEIR CHILDREN. AN EDUCATIONAL PROGRAM OF GROUP LECTURES AND DISCUSSIONS WAS PROVIDED FOR THE EXPERIMENTAL GROUP. BECAUSE OF POOR ATTENDANCE BY PARENTS DURING THE FIRST YEAR, METHODS OF MOTIVATING PARENTS TO PARTICIPATE IN THE PROGRAM WERE STUDIED. THE SECOND YEAR, 28 SETS OF LOWER SOCIOECONOMIC STATUS (SES) PARENTS WERE RANDOMLY ASSIGNED TO INCENTIVE GROUPS RECEIVING AN EDUCATIONAL PROGRAM. IN ADDITION, GROUP ONE RECEIVED A $50 BONUS, GROUP TWO CHOSE AN INCENTIVE UNDER $50 IN VALUE, GROUP THREE PARTICIPATED IN A TELEVISION DRAWING, AND GROUP FOUR RECEIVED NO INCENTIVE. GROUP FIVE RECEIVED NEITHER EDUCATION NOR INCENTIVE. AN UPPER SES GROUP RECEIVED THE EDUCATIONAL PROGRAM BUT NO INCENTIVE. THE THIRD YEAR SAMPLE WAS COMPOSED OF PARENTS OF 165 RETARDED YOUNG ADULTS ASSIGNED TO A PARENT EDUCATION MEETING GROUP, A TELEPHONE GROUP, OR A CONTROL GROUP. CLIENTS AND FAMILIES CONTINUED TO RECEIVE SERVICE FROM AGENCIES BUT THE TWO EXPERIMENTAL GROUPS WERE GIVEN THE EDUCATIONAL PROGRAM. PRE- AND POST-OBSERVER RATINGS WERE USED TO ASSESS THE WORKSHOP PARTICIPANTS AT THE BEGINNING AND END OF THE PROGRAM. RESULTS OF ALL THREE STUDIES WERE INCONCLUSIVE. PARENT PARTICIPATION IN THE EDUCATIONAL PROGRAM REMAINED POOR ALL THREE YEARS. INCENTIVE METHODS TRIED DURING THE SECOND YEAR WERE INEFFECTIVE AT INCREASING ATTENDANCE FOR THE MAJORITY OF PARENTS OF LOW SES STATUS. PARENT PARTICIPATION AND VOCATIONAL ADJUSTMENT WERE RATED DURING THE THIRD YEAR. RATARDATES WHOSE PARENTS WERE CONTACTED SIX OR MORE TIMES BY TELEPHONE GAINED IN WORK ADJUSTMENT RATINGS AND THOSE WHOSE PARENTS ATTENDED SEVEN OR MORE PARTICIPATION GROUP MEETINGS DETERIORATED IN THE RATINGS. PRE- AND POST-RATING INVOLVED THE USE OF DIFFERENT STANDARDS. THE RATING SCALES USED IN THE STUDY ARE INCLUDED IN APPENDIXES. (VO)