Exploring the relationship between gesture and student reasoning regarding linear and exponential growth

Leading middle school students to effectively reason with magnitude, small and large-scale quantities, and linear and exponential growth is a challenge facing science teachers in the U.S. working to implement the NGSS and its associated focus on crosscutting concepts. This paper examines the relationship between middle school students' gestures and their reasoning about quantitative growth. For this study the authors developed interview protocols on several topics that involve numbers increasing linearly and exponentially. Students' verbal and gestural responses during the interviews were transcribed, coded, categorized and analyzed. Results showed that students display a breadth of context-dependent gestures, that their verbal reasoning is associated with the type of gesture they produce, and that gesture-speech mismatches are present in middle school students' reasoning about scale. Implications of this study include design guidelines for an interactive system that standardizes and structures scalerelated gestures.