This study, which occurred within an introductory-level biology course, examined how participation in a large-scale reform effort (the Collaborative) affected a science professor's conceptions of teaching, teachers, and reform. The Collaborative brought together a community of people who were part of a culture and co-created a culture of reform-mindedness. It taught participants to view the classroom environment as a place where learning was cooperative, active, and negotiated. The study examined how the professor's teaching identity was modified and created by the reform effort as she mediated her participation. Data collection involved interviews/correspondence with four students and the professor, classroom observations, and field notes. Overall, although the professor was inclined to try reformist strategies in her classroom, the project failed to create pedagogical dissonance, resulting in her inability and lack of desire to fully accommodate reformist pedagogy. Though she aligned herself with other participants motivated to improve their practice, she was not dissatisfied with her pedagogy at the outset. She became increasingly frustrated with the misalignment of her needs and interests with those of the project. She had a highly developed identity as a scientist and educator and valued her role as an educator. (Contains 27 references.) (SM)