What Do We Know About Deepening Mathematics/Science Teacher Knowledge and How Well Do We Know It?
The KMD project found that the empirical literature provides considerable support for the idea that teacher content knowledge matters. For example, in mathematics, more knowledgeable teachers were more likely to link new problems to what students had already learned. Similarly, teachers who understood multiple representations of mathematics concepts were able to use these representations to further students' understanding. In contrast, teachers with less mathematics knowledge tended to focus on algorithms rather than on the underlying mathematics concepts. Likewise in science, teachers with deeper content knowledge were more likely than those with weaker knowledge to pose questions, suggest alternative explanations, and propose additional inquiries.
In all but one of 32 studies of interventions intended to deepen teachers' content knowledge, participating teachers' science/mathematics content knowledge increased. At a minimum, these results provide existence proofs that experiences aimed at deepening teachers' science/mathematics content knowledge can achieve this goal. The diversity of the programs investigated across these studies suggests that there is a variety of effective ways of structuring and delivering experiences to deepen teachers' science/mathematics content knowledge. The programs also differed in the grade range of participating teachers and the content that was addressed. At the same time, the fact that the interventions in these studies were multi-faceted makes it difficult to determine what practices are effective for a particular purpose.
Expert practitioners with different perspectives on what content knowledge matters, and experience with many different professional development programs shared insights about effective practices for deepening teacher content knowledge. In this case, asking specific questions -- about the design of particular interventions, the impact of particular facets of this work, and the evidence for those claims - led to more nuanced information than could be gleaned from the empirical literature, but without the benefit of systematic investigation.
