The goal of this study was to identify whether individual differences among students might influence the effectiveness of visualizations; in particular, concurrently presented alternative visualizations of chemical molecules. Thirty beginning organic chemistry students of varying prior knowledge completed: (1) a battery of tests measuring reasoning ability, spatial ability, and need for cognition and (2) an eye-tracking session, in which they viewed both ball-and-stick and potential plot representations, and answered interpretation and application questions. Eye movement patterns indicated that students tended to initially rely on the already familiar ball-and-stick representations, especially for more difficult application questions. As the task unfolded, though, students' choice of which representation to refer to was moderated by prior expertise and general reasoning ability.