This paper reports on a study of inquiry and teacher development in a middle school science reform project. A model was developed that examined the dialectical interaction between teachers' concerns about their classroom practice and the culture of their professional setting, the school. This model sees the interaction of these two concerns as a zone of proximinal development for teachers. An examination of the literature shows support for how this model can explain both the successes and the breakdowns that occur in this zone. The project, Scientific Process, Practice, and Presentation: Applying Resources and Knowledge (SPARK), is the source of the data for this study. The goal of SPARK is to promote and support systemic change within middle schools in terms of teacher practice, student activity, and school culture. Contains 18 references. (DDR)