Getting to the core of the apple: A theoretical view of the knowledge base of teaching

Language of the knowledge base of teaching is common parlance in educational circles today, yet the constructs under discussion are still unclear. Some educators talk of domains of knowledge, such as pedagogical content knowledge. Some talk of ways of knowing, such as practical knowledge. Others talk of credit hours of particular topics, such as curriculum and instruction. Still others talk of ways of doing, such as effective teaching practices. The purpose of this article is not to give a detailed account of the historical development of what we now think of as the knowledge base of teaching. Neither is it within the scope of the article to explore the various epistemologies from which discussions of the knowledge base emerge. Others have already initiated these conversations (Carter, 1990; Shulman, 1986a; Tom & Valli, 1990). Rather, the goal is to identify what others have said about what teachers do and know, to offer some clarifications, and then to integrate them in a theoretical framework that might be useful for those involved in the education and assessment of teachers. In the process, three issues are addressed: (1) why a theoretical framework is necessary; (2) what a comprehensive framework might consist of; and (3) how the proposed framework might be used.