Collaborative discussion is one of the most effective tools to deepen students’ understanding and engagement with texts. Discussion offers students the opportunity to build arguments and defend them with evidence, consider opposing points of view, elaborate ideas, and build complex webs of knowledge by revealing and furthering thinking. Unfortunately, the amount of time devoted to classroom discussion is measurable in seconds per day (Nystrand 2006), and when discussion does occur, the quality and depth of students’ discourse is often limited (Zwiers & Crawford, 2011).