This paper reports data from a program of research examining how teachers learn the practical, professional knowledge of teaching. Data collection focused on interviews with teachers immediately following a period of classroom observation. Interviews were spaced at monthly intervals when possible. The 15 participants included teachers in training, teachers in their first year of teaching, and several teachers withseveral years of experience. Of particular interest was the concept of "seeing" as applied to teachers' views of their work: the process of perception being regarded not as observation followed by selection and interpretation, but as a unified process in which observation is interpretive. The occurrence and significance of metaphors in teachers' accounts of their practical knowledge and the changes that occur in teachers' perspectives on their work as a result of events of practice were explored. The theoretical framework for the research is drawn from Schon's (1983) "The Reflective Practitioner." This paper explores the tension between theory and practice by considering excepts from interviews with two teachers, one in her first year of teaching and the other in her second year of teaching. (JD)