Data obtained through Western Kentucky University's Teacher Preparation Evaluation Program were analyzed to identify changes in teachers' perceived problems, concerns, and classroom behavior over a six-year period. Data were collected from teachers at four points: during the student teaching experience, and near the end of the first, third, and fifth years of teaching. Participants in the first cycle were obtained from the 1972 student teacher population. Starting with Cycle VI (1977), participants were choosen to increase the initial sample size and to reflect desired characteristics, particularly secondary level subject matter preparation. The data selected were from self reports, direct classroom observation, and ratings by students, peers, and supervisors. Findings indicated that teachers at all levels tended to regard student discipline and motivation as major problems in meeting their professional obligations. While concern about the impact of instruction on students was high for all teachers, it was of more concern for elementary inservice teachers than for secondary inservice teachers. The opposite was true for preservice and beginning teachers, in whom concern about their own teaching performance was highest. Differences in verbal interaction patterns emerged between elementary and secondary school teachers, and remained relatively constant across teaching levels. As teachers gained experience, they tended to perceive an increase in problems with pupils, administrators, and parents, while at the same time their concern about themselves as teachers was decreasing. They tended to have increasing concerns about instructional tasks even though their classroom teaching behavior greatly improved, particularly between the first and third years of teaching. (JD)