The Next Generation Science Standards emphasize engaging students in the practice of constructing explanations using disciplinary core ideas such as the structure of matter. Research has identified that students have difficulty both with constructing explanations and with constructing particulate views of matter, and therefore there is a need to research additional ways to support students in these areas. The present study investigated how students used gestures as they shifted from descriptions to explanations of phenomena involving gas pressure. Using case studies based on student interviews, we found that students used gestures differently when they provided descriptions and when they provided explanations. While giving descriptions, students used gestures to represent observable aspects of the phenomena. While giving explanations, students used gestures to simultaneously represent observable aspects of the phenomena and unseen mechanisms. We conclude that prompting students to use gestures while explaining phenomena may help improve the quality of their explanations by helping them link observable phenomena with underlying mechanisms.National Science Foundation under Grant No. DUE-1432424Ope
