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.
The need for a theoretical framework
The theoretical framework is based on a few assumptions which have been hotly contested throughout history in the educational forum.
The first assumption is that it is possible to create a big picture framework for organizing what beginning teachers need to know and be able to do apart from the normative aspects of teaching. Normative issues, such as the aims and purposes for teaching and schooling, must be decided within a particular context (e.g., subject matter, grade level, geographic area); however, there appears to be a knowledge base skeleton that transcends aims and purposes. The following section offers a view of this skeleton that is based on an integration of current work in the field.