This article examines the influence of a practicum teaching experience on two pre-service science teachers. The research is focused on examining a practicum in a secondary science department that actively promotes the teaching and learning of science as inquiry. We investigated the process through which the pre-service science teachers integrated their practical knowledge, and examined this in the context of the quantified reformed instruction they enacted. Using a mixed methods design, we have quantified these pre-service science teachers' practice using the Reformed Teaching Observation Protocol (Piburn et al. 2000), in concert with a narrative methodology drawn from in-depth interviews. Our analysis of the data indicates two important conclusions. The first is the importance of a consistently reformed image of science education being presented and practiced by both science teacher educators and cooperating teachers. The second is the recognition that a consistently reformed image may not be sufficient, of itself, to challenge pre-service teachers' views of science education. Pre-service teachers appear to be heavily influenced by their biographies and own science education. Consequently, it appears the extent to which a pre-service teacher identifies problems of teaching and learning, and then works toward possible resolution, influences their progress in shaping reformed views of science education.