Using Graphical Representation Critiquing Assignments as an Intervention to Strengthen Organic Chemistry Electron Pushing Mechanism Skills

Fostering relational understanding of science concepts requires that students engage in meaningful practice and consideration of content both inside and outside class. Calibrated Peer Review (CPR) is a text-based academic intervention that has improved students’ essay writing skills, content understanding, and critical thinking skills across many disciplines. We investigated whether the Assessment-Calibration-Explanation-Re-Assessment (A.C.E.R.) Learning Cycle intervention, a symbolic-based intervention inspired by CPR, could enhance students’ utilization of symbolic content, such as electron pushing arrow formalism in Organic Chemistry. Participants were administered formative assessments after reaction mechanisms were taught, calibrated by performing reflection exercises to score the electron pushing mechanism accuracy of carefully-selected examples from their peers, required to explain how they would rank the anonymous samples from best to worst, and answer related electron pushing mechanism questions. Participants’ course grades were higher than control group’s course grades. Paired samples t test indicated that participants’ Re-Assessment samples were significantly better than their Assessment samples. Moreover, participants expressed that the intervention had helped them understand electron pushing arrow mechanisms to a greater degree. Implications for instructors are suggested, including selection of meaningful mistakes for students’ analysis and modification of the CPR intervention for graphically-represented concepts.