Institutional review board approval was secured at Unity and UP (UnityIRB 2011-06 and UPIRB 2011). We thank our now graduated and always appreciated Unity undergraduate math education work-study research assistants Alexis White and Kieu Tran, who assisted in data entry and analysis, and we acknowledge professional development support from Unity College. We also thank Drs. Bodine, Lenhart, and Gross and Princeton University Press for the use of the draft versions of their textbook and Dr. Gross, the Smith lab at University of Maine–Orono, and the editors and reviewers of CBE—Life Sciences Education for feedback on earlier drafts of this paper.