Recognizing mechanistic reasoning in elementary students' engineering design discourse

Background: Helping elementary students think carefully and collectively about the details of their engineering design prototypes is a shared goal of engineering educators and curriculum developers. Mechanistic reasoning is one kind of thinking that engineering students can share with their design teammates to make sense of a prototype's performance. Purpose: By connecting existing frameworks from the science education literature to new data from classroom engineering activities, this article illustrates an approach to characterizing the mechanistic reasoning expressed in children's engineering design discourse. Method: We analyzed third- and fourth-grade students' discussions of their engineering designs-in-progress in two different community-contextualized curriculum units: one on holding back earth materials with retaining walls and the other on building accessible playground structures. Results: Across these disparate design challenge contexts, we show how elementary students' mechanistic reasoning discourse in engineering involved identifying the target performance of a design, naming entities that matter within a design and its environment, describing entity factors that are relevant to design performance, connecting factors to each other, and linking entities and factors back to the overall performance of the design as a whole. Conclusions: We argue that attention to these elements of mechanistic reasoning in students' design discourse may help educators responsively support students' analysis of their prototype performance.