This study further extends a conceptual framework that explores science teaching as a "practice" not reducible to the application of formal knowledge, but as informed by teachers' practical-moral knowledge. A hermeneutic model was developed to examine practical-moral knowledge "indirectly" by investigating teachers' commitments, interpretations, actions, and dialectic interactions between them. The study also aimed to analyze teachers' actions in terms of their interpretations and commitments as they realize "internal goods" of their practice. Ethnographic case studies of three science teachers were conducted through classroom observation, in-depth interviews and dialogues, and artifact analysis. A commitment of preparing students for national exams was common to the three teachers but was manifested differently in classroom practices. This commitment originated from interpretations about the duty of "good" teachers not "letting students and schools down". Other emergent commitments were commitments: to conceptual understandings, to "challenge" learners, and to social modeling. We present each with associated interpretations and actions. The concepts of practical wisdom (phronesis) and gap closing are used to characterize teachers' practical knowledge and its development respectively. Implications for teacher education are discussed. (Contains 5 tables, 2 figures and 6 notes.)