Unpacking the Gestures of Chemistry Learners: What the Hands Tell Us About Correct and Incorrect Conceptions of Stereochemistry

ABSTRACT

In this study, adults naïve to organic chemistry drew stereoisomers of molecules and explained their drawings. From these explanations, we identified nine strategies that participants expressed during those explanations. Five of the nine strategies referred to properties of the molecule that were explanatorily irrelevant to solving the problem; the remaining four referred to properties that were explanatorily relevant to the solution. For each problem, we tallied which of the nine strategies were expressed within the explanation for that problem and determined whether the strategy was expressed in speech only, gesture only, or in both speech and gesture within the explanation. After these explanations, all participants watched the experimenter deliver a 2-minute training module on stereoisomers. Following the training, participants repeated the drawing + explanation task on six new problems. The number of relevant strategies that participants expressed in speech (alone or with gesture) before training did not predict their post-training scores. However, the number of relevant strategies participants expressed in gesture only before training did predict their post-training scores. Conveying relevant information about stereoisomers uniquely in gesture prior to a brief training is thus a good index of who is most likely to learn from the training. We suggest that gesture reveals explanatorily relevant implicit knowledge that reflects (and perhaps even promotes) acquisition of new understanding.

Acknowledgments

We are grateful to Mike Stieff for very helpful comments on a rough draft of the manuscript. We also thank Melissa Herrett and Theodora Kmoutsakis for help with figures.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Supplementary material

Supplemental data for this article can be accessed on the publisher’s website.

Notes

1. Not all stereoisomers are chiral, but in our study we used chiral and chiral-looking molecules.

2. For example, the experimenter forgot to turn on the video camera. In another case, the experimenter did not stop a participant from holding the marker during the explanations, which inhibited gesture.

3. Some participants were not able to produce drawings with the same molecular formula and bonding order as given in the stimulus molecules.

4. There are no double bonds in the molecule in the figure, but some molecules used in the study did contain double bonds.

5. The molecule with a stereoisomer had an enantiomer, a diastereomer, and an enantiomer of the diastereomer.

6. Although there are different types of stereoisomers, in the current study we limited our prompts and instruction materials to molecules with mirror-image configurational enantiomers and, as a contrast, molecules with symmetry that do not exist in enantiomer form. We use the terminology “stereoisomer” and “stereochemistry” throughout. Some of the molecules used as stimuli exist in diastereomer form as well. The same strategies can be used to create a stereoisomer for diastereomers.

7. During each trial, participants were allowed to revise their drawing as many times as they desired but were then asked to restart their explanation from the beginning each time they did. Only the final drawing and explanation were included.

Additional information

Funding

This work was supported by NICHD R01-HD47450 and NSF BCS-0925595 to SGM and NSF SBE-0541957 (Spatial Intelligence and Learning Center) to Nora Newcombe (PI) and SGM (co-PI).