The purpose of this study was to explore preservice teachers' lived experiences in a lesson study focused on teaching and learning nature of science (NOS). The body of knowledge about shifting pre- and in-service novice NOS understandings is substantial. The focus of science education research is now exploring ways to move these informed NOS understandings into classroom practice (Abd-El-Khalick & Lederman, 2000b).

The research questions guiding the study were (a) how do preservice teachers' understandings of NOS shift as a result of the lesson study experience?, and (b) how does the reflective practice that occurs in lesson study influence preservice teachers' transition of NOS tenets into classroom practice? The participants in this study represented a sample of graduate preservice teachers, who were part of a middle and secondary science teaching alternative certification program in a southeastern university. In the first summer semester of this certification program, the participants were immersed in reform based science instruction; a section of which included NOS teachings (INTASC, 2002). In the following semester, participants were placed in a practicum setting; where the exploration of the preservice teachers' teaching of NOS was supported through the modified lesson study framework.

Data sources included the Views on Nature of Science-Form B (VNOS-b), interviews, and lesson study portfolios. Analysis of NOS understandings was guided by instruments found in literature associated with the VNOS-b (Lederman et al., 2002) and reflection (Ward & McCotter, 2004). Results showed successful transfer of NOS into classroom practice using the modified lesson study framework, with less success in the deepening of participants' NOS understandings. Of particular significance was that results indicated a deepening of NOS pedagogical content knowledge for those participants functioning at higher levels of reflection. The study's results contributes to two knowledge bases. First it provides insight to how lesson study can be used in the United States in alterative teacher preparation programs. Second, it contributes to what is understood about how to support the transition of NOS understandings into classroom practice.