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Instructional materials in organic chemistry include a wide variety of representations, such as chemical formulas, line-angle diagrams, ball-and-stick diagrams, and electrostatic potential maps (EPMs). Students tend to focus on explicit features of a representation while they are reasoning about chemical concepts. This study examined the affordances of electrostatic potential maps in students’ approaches when the maps were integrated into four foundational organic chemistry problems using an experimental design approach. First-semester organic chemistry students were surveyed from two different institutions, where they made predictions and explained their reasoning behind identifying an electrophilic site, predicting the product, selecting the faster reaction, and classifying a mechanism. Students were randomly assigned to one of four surveys that differed by the representation they were given for the prompts: chemical formula, line-angle diagram, ball-and-stick diagram, and EPM. Responses from students with EPMs were analyzed and compared to responses from students with the non-EPM representations. Results indicated that students with EPMs had higher performance depending on the problem. They were also more likely to cite electronic features such as electron density, nucleophilicity, etc., and were more likely to use causal reasoning in their explanations. This study offers evidence in support of affordances of EPMs in promoting students’ use of electronic features and causal reasoning. This evidence adds to the chemistry education literature by offering a potential means for promoting students’ use of electronic features and causal reasoning by incorporating EPMs into assessment items. Implications for instruction include using EPMs in both instruction and assessment as a tool to help students build skills around invoking electrostatics and causal reasoning to solve problems in organic chemistry.
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This content will become publicly available on December 10, 2025
Patterns in Explanations of Organic Chemistry Reaction Mechanisms: A Text Analysis by Level of Explanation Sophistication
Learning the language of organic chemistry, i.e., how to describe reaction mechanisms, is crucial to success in any postsecondary organic chemistry course. However, it is well-known that learners struggle with reasoning about and explaining reaction mechanisms beyond surface-level features. Multiple studies have sought to aid learners in developing these skills. Investigating the connections that learners make regarding reaction mechanisms through their explanations provides insight into how we can better promote the development of learners’ reasoning skills. In this study, we evaluate 20,000+ learner explanations of 90 reaction mechanisms. We use network analysis to explore patterns in keywords used by learners and visualize the word connections between them, based on their co-occurrence, within our entire data set, by reaction type, and by levels of explanation sophistication. Our results indicate that learners consistently rely on explicit surface-level features in their explanations with expected contextual variance by reaction type. This trend persists across the levels of sophistication, however, with improvements in the use of vocabulary and coherency as sophistication progresses. We hypothesize that this is evidence of learners actively working toward constructing understanding as they experiment with and refine their vocabulary until they are able to pare down their explanations in a coherent manner. This work offers insights for instructors seeking to promote the development of learners’ reasoning skills and for researchers interested in the development of machine-learning models to assist in evaluating learner explanations of reaction mechanisms.
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- Award ID(s):
- 2315626
- PAR ID:
- 10616033
- Publisher / Repository:
- American Chemical Society
- Date Published:
- Journal Name:
- Journal of Chemical Education
- Volume:
- 101
- Issue:
- 12
- ISSN:
- 0021-9584
- Page Range / eLocation ID:
- 5203-5220
- Subject(s) / Keyword(s):
- Lower-Division Undergraduate Organic Chemistry Reaction Mechanisms Explanations Network Analysis Chemical Education Research
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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