The PEPS was developed by administering a 60-item scale to 102 inmates and performing factor analyses. Factor mean scores, in descending order, were cognitive interest, personal control, self-preservation, outside contact, and self-assertion. Volunteers for the present study were recruited from 350 male prisoners participating in high school diploma studies. Discovering that most inmates had the same orientation toward participating in educational activities as the general public reinforced the generalizability of adult participation motives. The correspondence between Boshier's factors and study findings, however, was not consistent. With respect to factors identified by Houle in his work (cognitive control, goal orientation, activity orientation, and avoidance posture), avoidance posture appeared to be unique to prisoner participants. Avoidance motivation played less of a role in participation than any of the other reported motivations. 13 references and 2 tables