Research previous to this study suggested that the efficiency of teachers increases to a zenith and from there decreases to a degree of inefficiency. This research led to a hypothesis that teaching characteristics can be associated with career development stages. In phase I of this study (conducted in 1983) 145 principals from 2 midwestern states were surveyed on the question of career stages. Their responses yielded 161 characteristics which they felt differentiated one instructional stage from the other. These characteristics were then used as the basis for phase II of the study, in which 50 high school principals from each of six states in the mid-south were surveyed to determine if teaching characteristics indicating teacher efficiency could be consistently associated with various stages of career development (analysis was based on results from 103 respondents). The subjects were requested to assign items on the survey to corresponding levels of experience they thought described teachers at certain stages of their career. Results of this study supported the proposed hypothesis and may be used to identify teachers who need staff development. However, further research is necessary to more thoroughly validate the model. (RG)