Despite being a prerequisite for many STEM majors, introductory organic chemistry is

notorious for high DFW rates, reflecting persistent struggles with writing reaction mechanisms. Rather

than treating these difficulties as deficits, we adopt David Hammer’s Resources Framework to foreground

the richness of students’ ideas. We argue that students arrive with heterogeneous but sensible conceptual,

epistemological, procedural, and representational resources that can be recruited and refined for

mechanistic reasoning. The problem, then, is not absence of knowledge, but the cueing, coordination, and

stabilization of resources under particular task framings.

We conducted 20 think-aloud interviews with undergraduate organic chemistry students. Participants were

asked to work through several typical organic reaction tasks (drawing a reaction mechanism for given

reactants, adding curved-arrow notations, and predicting reaction products) while explaining their

reasoning at each step. All interviews were video-recorded and transcribed, and qualitative coding

analysis is underway. We are examining the data for evidence of the intuitive knowledge elements and

reasoning strategies students invoke.

Preliminary observations suggest that students draw upon a rich set of cognitive resources when reasoning

through reaction mechanisms. Many students began by recalling memorized “textbook” mechanisms, but

when confronted with an unfamiliar or puzzling aspect of a reaction, they shifted into a more generative

mode of reasoning. For example, one student invoked a “magnets” analogy for arrow pushing, describing

electron pairs as being “pulled” toward positively polarized centers and “repelled” by negative regions,

which appeared to cue electron-flow schemas and subsequent representational checkpointing (e.g.,

making lone pairs and partial charges explicit). Students also considered fundamental principles (such as

charge stability or steric effects) to evaluate their ideas and iteratively refined their mechanisms (revising

steps and checking for consistency). These patterns indicate that even when unsure how to proceed,

students actively leverage prior knowledge and heuristics to make sense of the chemistry. We anticipate

that our full analysis will identify several common intuitive reasoning patterns, illustrating how learners’

existing cognitive resources serve as productive starting points for developing more expert-like

mechanistic understanding.

Abdul Rauf

University of Illinois Chicago