for students to change their minds, argue, and revote. In position-driven discussions, everyone is focused on the same phenomenon but is required to commit to one position or another and to argue for their respective predictions or theories. Everyone is also free to change positions on the basis of another person’s evidence or arguments—typically with the proviso that one says, as specifically as possible, what it is in the other’s position that one finds useful or persuasive.
Position-driven discussions are designed to push for divergence in predictions and theories. They also capitalize on the wide variety of life experiences and resources inherent in an ethnically and linguistically diverse group of students. Such discussions are a powerful form of “shared inquiry” that mirror the discourse and discipline of scientific investigation.
In position-driven discussions, as in most effective classroom talk and argument formats, the teacher’s role is to help students explicate their positions as clearly and cogently as possible, not indicating, even subtly, how close to the “right” answer they may be. The teacher does not evaluate student contributions as correct or incorrect, as is often common in traditional teacher-guided discussion or recitation. Instead, the teacher typically supports students by revoicing their contributions and pushing for clarification. This helps both the speaker and the rest of the class move toward a greater understanding of their own and everyone else’s reasoning.
This emphasis on having a clearly explained theory or position over having a correct theory or position continues until the demonstration is run and students see the actual outcome. This focuses students on finding explanations or answers in the outcomes of evidence, not merely in authoritative sources like textbooks and teachers.
One important aspect of a position-driven discussion is the framing of the question with which the discussion is launched. This is not always an easy task. It requires that the teacher produce a clear, easily understood question that will provoke a range of reasonable responses and positions, none of which can appear obviously correct. In addition, the question must be carefully selected and sequenced among other science-related tasks so as to advance the thinking of the group as a whole. It is unreasonable to expect a teacher to develop such framing questions without the support of a rigorous, coherent curriculum, colleagues, or an instructional coach.