What We Know About Deepening Teachers' Content Knowledge: Engaging Teachers in Content-based Investigations in Mathematics/Science

Professional learning opportunities for teachers of mathematics and science have increasingly focused on teachers' content knowledge. Learning opportunities aimed at deepening teachers' content knowledge often include a strategy of engaging teachers in content-based investigations that target specific concepts-for example, focusing teachers on the content embedded in activities they use with their students, or engaging teachers in investigations designed specifically for adult learners. Advice from experienced practitioners offers guidance for efforts to engage teachers with content-based investigations as a strategy for deepening their disciplinary content knowledge and/or ways of knowing mathematics/science. Insights provided by a group of expert practitioners with diverse backgrounds and experiences in working with teachers included the following ideas:

• Teachers can deepen their understanding of mathematics/science content by experiencing the student materials as learners.
• Teachers need to be supported as adult learners of the content through engaging activities that build on their prior knowledge, and through instructional experiences that are appropriately scaffolded and challenging.
• Teachers need to see the connection between how they are encountering the content and how the topic appears in the grade-level content.
• It is important to provide teachers opportunities to experience what it means to "do" mathematics/science.
• Developing teachers' understanding of ways of knowing in mathematics and science requires going beyond modeling to an explicit focus on disciplinary habits of mind.
• To help teachers understand mathematics/science as ways of knowing, it is important to choose problems that are amenable to discussions of the nature of the discipline, ideally providing opportunities to investigate ideas from more than one perspective.
• It is important to "debrief" teachers' learning experiences, both from the perspective of the nature of the discipline and implications for classroom practice.
• Reading about how mathematicians/scientists generated knowledge can help teachers understand the nature of the disciplines.

Teacher Content Knowledge Matters

Empirical evidence demonstrates that teachers' mathematics/science content knowledge makes a difference in their instructional practice and their students' achievement. Consistent findings across studies include:

• Teachers' mathematics/science content knowledge influences how teachers engage students with the subject matter.
• Teachers' mathematics/science content knowledge influences how teachers evaluate and use instructional materials.
• Teachers' mathematics/science content knowledge is related to what their students learn.

Research on Engaging Teachers in Content-based Investigations in Mathematics and Science

Research studies of seven interventions that engaged teachers in content-based investigations in mathematics, as one of several strategies, were identified in a search of the published literature. All seven studies provided evidence of positive effects on teachers' mathematics content knowledge (Basista & Mathews, 2002; Clark & Schorr, 2000; Garner-Gilchrist, 1993; Geer, 2001; Hill & Ball, 2004; Sowder, Philipp, Armstrong, & Schappelle, 1998; Swafford, Jones, & Thornton, 1997; Swafford, Jones, Thornton, Stump, & Miller, 1999). Teacher participants in the interventions ranged from grade 1 to grade 10. Across the studies, topics in number and operations, algebra, geometry, measurement, and data/probability/statistics were addressed, as well as mathematical processes of communication, representation, and problem solving. Although none of these studies investigated the unique contribution of the strategy of engaging teachers in content-based investigations, consistent positive results across programs support claims regarding its effectiveness in deepening teachers' mathematics content knowledge.

The literature search surfaced 20 research studies of professional development programs that included engaging teachers in content-based investigations in science. Each intervention included several strategies, and none was designed to measure the unique influence of attention to engaging teachers in content-based investigations. Still, they predominantly reported positive results regarding of the effectiveness of the programs in deepening teachers' science content knowledge (Clermont, Krajcik & Borko, 1993; Freeman, Pounders & Teddlie, 1994; Greenwood & Scribner-MacLean, 1997; Irving, Dickson & Keyser, 1999; Jarvis, Pell & McKeon, 2003; Jones, 1997; Jone, Rue & Carter, 1998; Lord & Peard, 1995; Odom, 2001; Pardhan & Wheeler, 2000; Puttick & Rosebery, 1998; Radford, 1998; Robardey & Others, 1994; Shymansky, Woodworth, Norman, Dunkhaus, Matthews & Liu, 1993; Storti, 1999; Summers & Kruger, 1994; Summers, Kruger, Mant & Childs, 1998; Tuan & Chin, 1999; van Driel, Verloop & de Vos, 1998; Wang, 2001). Teacher participants in the studies ranged from Kindergarten to grade 12. Although earth, life, and physical science were represented, physical science was the most frequently studied content area.