University students’ understandings of concept relations and preferred representations of continuity and differentiability

The aim of the study reported in this paper is to investigate how students understand continuity and differentiability during and after a calculus course. The students’ choices of representations, both claimed and acted, were also studied. The study is part of a larger study of four student groups taking a calculus course. 207 students answered a questionnaire during the course and of them, 11 were interviewed after the course (the ones in this paper). Answers in questionnaires and interviews were categorised and compared. All students who preferred formal theoretical representations, and only those students, were able to produce formal proofs. The students’ stated and acted preferencesof representations were quite coherent, with only a few inconsistencies.