Teachers learning from professional development in elementary science: Reciprocal relationships between formative assessment and pedagogical content knowledge

Formative assessment, the assessment of student understanding to inform learning, has been shown to be a teaching practice that has powerful positive effects on student learning. Pedagogical content knowledge (PCK), teachers' knowledge specific to teaching particular subject matter, has been posited as an important resource for teachers engaging in formative assessment. However, no research has been conducted into the role of PCK in teachers' formative assessment practice. This study examined relationships between teachers' formative assessment and pedagogical content knowledge in the context of a professional development program that engaged eleven elementary science teachers in analysis of samples of their students' work related to electric circuits. It investigated both the ways that teachers' PCK contributed to their formative assessment practice, as well as the opportunities created through formative assessment for teachers to build PCK. Analyses showed that teachers both used and built pedagogical content knowledge through their engagement in formative assessment. Teachers built knowledge of student understanding though interpretation of the student work, and used that knowledge in subsequent interpretation. The assessment tasks supplied by the PD and the corresponding student work provided evidence of a range of and patterns in student thinking. In general, teachers made productive use of the evidence available in the work, and used multiple approaches to interpretation that created opportunities to build different kinds of PCK. However, when teachers were engaged in the task of interpreting larger sets of work in focused ways and constructing a rubric, their approach to interpretation obscured the patterns available in the work, and constrained their opportunities to build PCK. Teachers used knowledge of the local curriculum and instructional strategies as they engaged in formative assessment, knowledge derived from their own science learning experiences in the PD, and their concurrent teaching practice. Through their talk and collective analysis, teachers co-constructed an orientation toward the nature of classroom science in which students were responsible for applying concepts provided by the teacher to appropriate situations. Patterns in teachers' talk about assessment were consistent with this orientation. There was also evidence that teachers' expressed PCK was consistent with this orientation. More often, however, teachers did not describe classroom practice to a level of detail that supported connections to a specific orientation. The findings provide support for proposals that PCK is an important resource for teachers' formative assessment practice, as well as providing evidence that formative assessment represents an important opportunity for teachers to build PCK. Future research and professional development in this area needs to consider the role of material resources such as curriculum and assessment tools, as well as the role of teachers' orientations to the nature of classroom science.