| Effective science teaching requires in-depth content knowledge and pedagogical understanding of the subject matter taught. However, national indicators continue to show those teaching in the physical sciences are inadequately prepared and of these, the least prepared are middle school teachers who teach earth science. To address the critical need for better-prepared middle school science teachers this study examined a professional development program implemented within a framework of topic-specific pedagogical content knowledge (PCK) as an effective model for in-service teacher learning in earth science. Pre- and posttests, structured journals, classroom observations and semi-structured interviews provided for a mixed-methods approach for data collection, analysis and inference processes in the form of a parallel mixed-model design. The study findings showed: (1) Topic-specific PCK is a viable guide for in-service teacher learning in professional development settings, (2) Teachers experienced difficulty when asked to conceptualize their own construction of knowledge, (3) When implementing new science curriculum (e.g. FOSS Earth History science kit), beginning and experienced teachers encountered similar learning challenges (e.g., antagonistic dilemma), and (4) Findings illustrated the essential role of subject-matter knowledge in teachers' development of topic-specific PCK. Several implications for in-service teacher education are suggested. First, in order to foster effective teacher learning of new science content it is recommended that teachers gain a strong understanding of the fundamental concepts in the subject matter to provide a foundation on which topic-specific PCK can then be developed. Second, when learning new science content the findings indicated that both experienced and beginning teachers would benefit from teacher induction models to aid in the development of the fundamental concepts related to new subject matter. Third, reflection and asking questions are important components of scientific inquiry, thus teachers need to learn how to reflect and ask productive questions themselves. |
