We often use Evidence-Centered Design to develop tasks that will elicit evidence of what we believe is important for students to know and do. A key part of this process is the iterative refinement process in which we alter the task to elicit different knowledge or resources from the students based on our analysis of their responses. We used this approach to design a prompt asking students to draw an organic chemistry mechanism of a one-step intramolecular ring closure, which has been noted as a difficult reaction for students. We added scaffolding to activate students’ ideas about the charge distribution in the molecule before they drew the mechanism to support them in predicting the product for the reaction. Over 3 years, we administered multiple iterations of the prompt to students based on the responses of the students from the previous year. Each version revealed different resources that students were using to answer the question based on how we framed the scaffolding. Across the different versions of the prompts, some changes made were found to support students in answering the question, while others ended up causing student to mis-apply their knowledge and lead them down a path to an incorrect answer. These versions of the prompts will be compared, and lessons learn about prompt wording and timing will be discussed.

Best-laid plans oft’ go awry: How changing the scaffolding may have unforeseen consequences in student responses

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.