Previous studies have shown that students who have completed differential and integral calculus often accept and employ empirical arguments as proofs, but this is not the case for students who have had at least one upper-level proof course; these students tend toward the use of deductive proofs. This paper finds that a majority of the students surveyed preferred deductive arguments at the beginning of a transition-to-proof course, though there was a sizeable minority who preferred empirical arguments. However, most of the students who initially preferred empirical arguments shifted their positions and preferred deductive arguments by the end of the semester. Finally, the paper shows that by the end of the semester students are more consistent in choosing deductive arguments.