Conceptualization and operationalization of group thinking sustainability in dialogic collaborative problem solving

•Group thinking sustainability describes sustained engagement in high-order thinking.•Group thinking sustainability involves reciprocity, productivity, and constructiveness.•Group thinking sustainability is quantified as the length of a turn-taking sequence.•Group thinking sustainability helps explain the variety of group outcomes. Peer talk shapes the trajectory of group thinking. Studies have explored productive peer talk moves that can facilitate high-order group thinking, yet few have focused on the extent to which students consecutively take up these talk moves to sustain group thinking. There is no consensus on how to understand or measure the sustainability of productive peer talk. This study establishes a construct to help characterize a group's capacity to consecutively engage in high-order collective thinking and to investigate the impact of such sustainability on group outcomes. The proposed construct, group thinking sustainability (GTS), was conceptualized as a three-level nested hierarchy (comprised of reciprocity, productivity, and constructiveness) and further operationalized as the average length of a corresponding overt turn-taking sequence in group discussions. This study applied this construct to a sample of 168 primary school students who were divided into groups of four and asked to collaboratively solve three mathematical problems within 30 minutes. The results revealed that GTS can help characterize and differentiate a group's capacity to sustain productive peer talk. GTS can also help predict group outcomes and explain why some groups were more successful than others. This study provides novel insights into understanding and measuring GTS across groups. It also suggests a three-level scaffolding (i.e., turn-taking, productive talk, and knowledge construction) that teachers can use to support sustainable group thinking in collaborative peer talk.