As part of a larger research study, this paper describes calculus students' reasoning about the Intermediate Value Theorem (IVT) in verbal, written, and graphical form. During interviews, students were asked to verbally describe the IVT in their own words. They then provided written descriptions, watched video of their verbal descriptions,…

This paper presents an assessment tool which can be used during the first weeks of calculus to measure students' visual thinking skills. We have developed and applied this instrument in classes for the last three years, tabulating results and interviewing students on a regular basis. We discuss our findings and provide hints to using the…