Conceptual Fluency: Switching Between Pre- and Post-Threshold Assumptions of Molecular Dynamics

Abstract

We present preliminary analysis of chemistry graduate students' and secondary chemistry teachers' assumptions about mechanisms of chemical phenomena, around a set of threshold concepts. Chemistry education literature largely identifies pre-threshold assumptions as naive/alternative conceptions not particularly useful in understanding chemical phenomena. In the context of molecular dynamics, a threshold is considered to exist between thinking deterministically vs. probabilistically. We argue that (a) a deterministic perspective is as useful as a probabilistic one, (b) even experts implicitly exhibit (do not lose) deterministic assumptions, (c) probabilistic mental models are built on top of deterministic models, using multiple instances of the phenomena of interest, and (d) expertise involves willfully switching between pre- and post-threshold assumptions.