Interlocking models in classroom science

Both professional and classroom-based scientific communities develop and test explanatory models of the natural world. For students to take up models as tools for sensemaking, practice must be agentive (where students use and revise models for specific purposes) and conceptually productive (where students make progress on their ideas). In this paper, we explore principles to support agentive and conceptually productive modeling. One is that models can "do work"; that is, participate in students' sensemaking by offering resources, making gaps visible, or pushing back on modelers' understandings. A second is that working across, and seeking to align, multiple models-what we explain as interlocking models-supports models to do work. A third is that modeling activity can support fine-grained conceptual progress. We detail how we used these ideas to guide and refine the design of a fifth-grade investigation into the conservation of matter across phase change. We identify four ways that models participated in students' sensemaking as they interlocked: by providing contradictions, constraints, representational surplus, and gaps for students to engage with. We discuss how designing for models to be co-participants in sense-making and to interlock can provide productive paths forward for curriculum designers, researchers, and teachers.