Advancing student thinking
Upon noticing the substance of their students chemical thinking, a teacher may decide to advance their students' thinking toward a curricular aim. Here we will consider the ways in which teachers may decide to do so according to our formative assessment model of enactment. This model was derived from rigorous analysis of classroom videos of experienced science teachers (many of whom are chemistry teachers, most are teacher leaders in their school district) doing formative assessment activities with their students.1 Excellent science teachers have a broad repertoire and use all of these different kinds of teaching moves in different moments, depending on the in-the-moment purposes that teachers have which are shaped by knowing the specific students and the challenges they are facing at that moment, as well as in the context of the overall lesson purposes. Excellent teachers decide to advance their students' thinking when they intend to move students toward specific learning goals by developing students’ understanding using their own or others’ ideas. These advancing acts may be categorized as more directive or more responsive in nature.