Engaging students in productive science discussions is no easy task. Teachers have little difficulty eliciting a wide range of science ideas from students; however, the challenge lies in how to support students to develop and revise these ideas over time (Harris et al., 2012). During productive science discussions, teachers support students in working with and on each other’s ideas—comparing, revising, building on, combining or refuting ideas using evidence—in order to construct knowledge and evidence-based explanations of events (see principles of productive disciplinary engagement, Engle & Conant, 2002). This focus on working with and on students’ evolving ideas is pedagogically challenging not to mention uncomfortable for teachers who may not be used to entertaining the intellectual merits of canonically incorrect responses. However, supporting students in reasoning publicly through talk is a worthy pursuit as it plays a critical role in student learning and reflects the nature of science as a discipline (Bereiter, 1994; Engle & Conant, 2002; Mercer, 2008; van Zee, 2005).