In this paper, we present data from an exploratory study that aimed to investigate the
ways in which, and the extent to which, undergraduates enrolled in a transition-to-proof
course considered examples in their attempted proof constructions. We illustrate how
some undergraduates can and do use examples for specific purposes while successfully
constructing proofs, and that these purposes are consistent with those described by
mathematicians. We then examine other cases in which students used examples
ineffectively. We note that in these cases, the purposes for which the students attempted
to use examples are again appropriate, but the implementation of their strategies is
inadequate in one of two specific ways. On this basis we identify points that should be
borne in mind by a university teacher who wishes to teach students to use examples
effectively in proof-based mathematics courses
