It seems self-evident that teachers must know the subject matter they are required to
teach (Kennedy 1998). Teachers should have deep and complex understandings of
science concepts, be able to make connections among science concepts or topics,
and be able to apply science concepts to explain natural phenomena or real-world
situations. In addition, teachers should be able to engage in inquiry related to the
practice of science, as they generate questions, design and carry out investigations,
analyze and draw conclusions, and communicate findings using multiple formats
(National Research Council 2000). Furthermore, teachers should be able to develop
arguments and justify their ideas or solutions based on evidence (Lemke 1990).
Teachers’ knowledge of subject matter is a particularly important issue in science
education, as many science teachers have only limited preparation in the science
disciplines. They often have the same misconceptions or alternative frameworks
about science as do their students (Abd-El-Khalick et al. 1998; Smith and Neale
1989). Teachers who possess subject matter expertise and the ability to represent the
subject matter to their students are more likely to engage in conceptually rich,
inquiry-based activities that facilitate student learning, whereas teachers with weak
subject matter knowledge are more likely to rely heavily on the textbook as the
primary source of subject matter content (Carlsen 1991; Tobin and Fraser 1990).
This is problematic for student learning, since science textbooks generally fail to
address students’ misconceptions and teachers with weak science knowledge are
unable to clarify students’ confusions (Donovan 1997).