Resa M. Kelly

The effect that comparing molecular animations of varying accuracy has on students’ submicroscopic explanations

In this qualitative study, we examined how a group of seventeen first semester General Chemistry students responded when they were shown contrasting molecular animations of a reduction–oxidation (redox) reaction between solid copper and aqueous silver nitrate for which they first viewed a video of the actual experiment. The animations contrasted in that they portrayed different reaction mechanisms for the redox reaction. One animation was scientifically accurate and reflected an electron exchange mechanism, while the other was purposefully inaccurate and represented a physical exchange between the ions. Students were instructed to critique each animation for its fit with the experimental evidence and to ultimately choose the animation that they felt best depicted the molecular level of the chemical reaction. Analyses showed that most students identified that the electron exchange animation was the more scientifically accurate animation; however, approximately half of the students revised their drawings to fit with the inaccurate physical exchange animation. In addition, nearly all students thought that both animations were correct and useful for understanding salient information about the redox reaction. The results indicate that when students are shown contrasting animations of varying accuracy they make errors in deciding how the animations are supported and refuted by the evidence, but the treatment is effective. Contrasting animations promote students to think deeply about how animations fit with experimental evidence and is a promising way to engage students to think deeply about animations.

EXPLORING THE DESIGN AND USE OF MOLECULAR ANIMATIONS THAT CONFLICT FOR UNDERSTANDING CHEMICAL REACTIONS

Understanding chemical reactions conceptually involves recognizing characteristics of observable phenomena and envisioning how atoms, ions and molecules move and interact to cause the macroscopic changes. Our research focuses on the development of effective strategies for designing and presenting visualizations (videos and animations) to assist students with making connections between macroscopic and molecular level behaviors of chemical reactions. Specifically, we study how students, who view videos of a redox reaction that exhibits obvious signs of macroscopic chemical change, can determine which molecular animation of a set of contrasting animations is best supported by its fit with experimental evidence. Herein we describe how we develop our videos and animations, and how students are learning from this animation task. Students who select inaccurate animation models are often enticed by a model that is easier to explain and fits with their understanding of reaction equations. We note that even though students indicate a preference for one animation over another, they often revise their drawn representations to fit with features from multiple animations. With the assistance of eye tracking research, we are gaining a better understanding of what students view and how they make sense of it.