This five-year study gathered data on 174 prospective teachers through personality tests, self-evaluation forms, and sound films of student teaching behavior, and examined the effects of three kinds of psychological feedback on teacher preparation, personality, and behavior. Subjects were divided into four groups--one for control and three for feedback treatment, which involved minimally one or more personal interviews with a psychologist (Assessment Feedback). The first feedback group received only Assessment Feedback; the second, in addition to receiving Assessment Feedback, was permitted to view the sound films (Behavior Feedback); and the third, after receiving Behavior Feedback, was placed in student teaching situations judged maximally facilitating by observers. In general, students with feedback evidenced more self-confidence, classroom ease, and positive attitudes toward observation procedures. In regard to two propositions about feedback (students would become more receptive to pupil feedback and would increase characteristics related to effective teaching), changes were not observed between different treatment groups but rather between the beginning and end of preparation and between polled experimental and control subjects. Striking differences between elementary and secondary education majors were recorded. (A chapter on the related Mental Health in Teacher Education Project, 13 appendixes of measurement instruments, and a 45-item bibliography are included.) (LP)