This article reports on a collaboration project between South Africa and Sweden, in which we want to investigate whether the emphasis in undergraduate mathematics courses for engineering students should be more conceptual than the current traditional way of teaching. On the basis of a review of the distinction between conceptual and procedural knowledge, an analysis of student solutions to tasks designed to be solved with a conceptual approach but "proceduralized" by the students sheds some new light on this classical distinction. It is argued that the distinction can be operationalized in test items in a meaningful way but that caution needs to be taken in interpreting the results considering the complex interdependence of these constructs when doing mathematical work. (Contains 2 notes and 6 figures.)