Presented By: Department of Chemistry
Representations and Models: Probing Student Understanding via Benzene
Justin Pratt | University of Rhode Island
Studies report that organic chemistry courses have increased failure rates, lowered retention, and decreased student interest, prompting a need to understand student learning difficulties in these contexts. Organic chemistry professors report that student difficulties stem from misunderstandings of fundamental general chemistry topics and the complexity of organic chemistry topics, such as resonance and electrophilicity/nucleophilicity. One notable topic is aromaticity, a foundational concept in organic chemistry that appears in mechanisms and processes across STEM fields and requires connecting difficult concepts like resonance and electrophilicity/nucleophilicity. In fact, studies have shown that practicing/advanced chemists struggle with aromaticity. As such, to promote effective learning and practicing chemists in understanding aromaticity, both undergraduate and graduate students—from various class levels—participated in semi-structured interviews focused on 1) identifying aromatic, antiaromatic, and nonaromatic structures and 2) describing and defining aromatic structures and properties using models of Benzene. In these interviews, students used various representations to draw on a range of activated cognitive resources. Using inductive and deductive coding, researchers identified the resources and representational competence skills students invoked to discuss and describe aromaticity when given physical models of benzene. Results show that students can interpret these models with varied success, regardless of educational level. While some students relied on memorization to interpret the models, others used representational competence skills and discussed different uses of the various 3-D molecular models for teaching and learning aromaticity. Surprisingly, without explicit prompting, students discussed various limitations and affordances for these models, dependent on the model’s design and their own content knowledge. This presentation will share student ideas, focusing on their interpretations across multiple physical models and how electronic, bonding, and orbital resources shaped their discussions.