By passing the 1968 Vocational Education Act with its special provisions for cooperative education, Congress has highlighted the value and rapid growth of on-the-job programs. However, with this increased emphasis on cooperative education comes the need for investigating the present practices of selecting and preparing the on-the-job trainer assigned to a student-learner. For the most part data for the study was gathered by reviewing related literature and visiting a sample of nine 2-year institutions to interview teacher-coordinators. An analysis of the interview findings led to the conclusion that the selection of the on-the-job trainer was under the control of the teacher-coordinator through his approval or disapproval of the cooperating employer. It was also concluded that the on-the-job trainer was given little if any planned preparation before he undertook his teaching task. A significant recommendation of this study is that teacher-coordinators must take advantage of their responsibility and position to control the selection and preparation of the on-the-job trainers. This Ph.D. dissertation was submitted to the Ohio State University. (Author/JS)