This study enlisted a refutation text to foster conceptual change among 71 preservice teachers of mathematics education in situations that might elicit the use of the representativeness heuristic. Statistically significant differences were found between respondents’ pre- and post-tests, with more than half exhibiting normative reasoning after prior use of the heuristic. Analysis of their written explanations revealed differential patterns in their reasoning across two effect categories. Implications for misconception research and practice are discussed.