Trainees in a Public Service Employment program may find work training as paraprofessional aides in manpower agencies, social services, and human services. The work experience is valuable for the trainees. However, the actual structure of their training needs close attention. Supervisors are likely to rate the effectiveness of on-the-job training highly, while trainees give at least equal credit to the "common sense" which they bring with them to the job. Also, there may be little consistency in the training experience of different trainees. One answer to this problem is for employers to be more flexible in accepting the practical experience and "common sense" of the trainees as a substitute for more formal requirements, while at the same time formalizing the necessary on-the-job training into a regular curriculum. Transferability and placement prospects for trainees in paraprofessional slots are limited, especially in view of the tight job market. (Also included is a 22-item bibliography and a list of tables.) (Author)