Standing fast: Translation among durable representations using evanescent representations in upper-division problem solving

Mastering problem solving requires students to not only understand and apply physics concepts but also employ mathematics and mathematical representations (sketches, diagrams, graphs, gestures, equations and spoken language) skillfully. As part of a larger project to investigate problem solving processes among upper division physics students, we investigate how students coordinate among multiple representations while solving problems. Data for this study is drawn from an upper-division Electromagnetism I course, where students engage in individual oral exams. We do moment-by-moment analysis of students' problem solving to see how they translate between durable representations (diagrams, written mathematical equations) with the help of evanescent representations (gestures, words); and how they build up durable representations where they can "stand fast" later. In this paper, we present the case of Larry as an exemplary case for problem solving. Larry starts from a durable representation (diagram) and builds up from there using evanescent representations (gestures and words), standing fast on the diagram. He later translates to a different kind of durable representation (mathematics), where he reasons and answers the original problem.