A study examined the effects of a mandatory participation requirement on participant attitude toward and subsequent progress in a professional development program. Eight of the 24 schools in the Arkansas postsecondary vocational-technical school system were selected for the study. Participation in a professional development program was mandatory for those instructors hired after program implementation. Those hired prior to implementation were exempt from the mandatory participation requirement but were encouraged to participate voluntarily. An attractive incentive program for participation applied to both groups. Instructors and administrators completed a 48-statement instrument based on a 5-point response scale. Survey return rate was 100 percent. Progress was defined as the number of self-instructional Performance-Based Teacher Education curriculum modules an instructor had completed (out of a total of some 125). Data indicated that administrator attitude toward the program had no effect on or, in fact, had a negative influence upon instructor attitude. Regardless of the means used to ensure participation, instructor attitude toward the program had a high degree of effect on that instructor's progress within the program. No significant difference existed between attitudes expressed by or the progress of instructors whose participation was mandated and those who participated voluntarily. (YLB)