Science teacher educators (STEs) have key roles in the educational system through their preparation of pre- and in-service science teachers and in implementing future-oriented policy reforms. Given the complexity and importance of their role, what types of knowledge do STEs need? STEs come from a range of backgrounds and there are few systematic…

Describes the development and validation of an instrument on Student Perceptions of Teachers' Knowledge (SPOTK) in relation to their pedagogy. Uses features of teachers' knowledge from the research literature related to instruction, representation, subject matter knowledge, and assessment of students' understanding to generate categories in the…

Describes a study of preservice elementary teachers' (n=179) perceptions of geologic time. Finds that the respondents perceived events in Earth's geological past as falling into three distinct clusters: extremely ancient, less ancient, and geologically recent. Finds also that the teachers' grasp of relative time is more secure than their grasp of…

Explores the tension between subject knowledge and pedagogic content knowledge in elementary teacher education by documenting students' and inservice teachers' learning about forces in the context of floating and sinking. Describes significant features of the learning process and examines subject-specific aspects of learning by demonstrating how…

Reports on the Iowa Project, a broad effort in 20 school districts where a Science-Technology-Society (STS) approach was emphasized through a constructivist philosophy of teaching and learning. Results indicate the project's success in four areas: strengthening teacher confidence and knowledge base, encouraging teachers' use of innovative…