Building mental models of a reaction mechanism: the influence of static and animated representations, prior knowledge, and spatial ability

Abstract

In chemistry, novices and experts use mental models to simulate and reason about sub-microscopic processes. Animations are thus important tools for learning in chemistry to convey reaction dynamics and molecular motion. While there are many animations available and studies showing the benefit of learning from animations, there are also limitations to their design and effectiveness. Moreover, there are few experimental studies into learning chemistry from animations, especially organic reaction mechanisms. We conducted a mixed-methods study into how students learn and develop mental models of a reaction mechanism from animations. The study (N = 45) used a pre-/post-test experimental design and counterbalanced static and animated computerized learning activities (15 min each), plus short think-aloud interviews for some participants (n = 20). We developed the tests and learning activities in a pilot study; these contained versions of an epoxide opening reaction mechanism either as static (using the electron-pushing formalism) or animated representations. Participants’ test accuracy, response times, and self-reported confidence were analyzed quantitatively (α = 0.05) and we found that, while participants showed a learning effect, there were no significant differences between the static and animated learning conditions. Participants’ spatial abilities were correlated to their test accuracy and influenced their learning gains for both conditions. Qualitative framework analysis of think-aloud interviews revealed changes in participants’ reasoning about the test questions, moving toward using rule- and case-based reasoning over model-based reasoning. This analysis also revealed that dynamic and transitional features were incorporated into participants’ working mental models of the reaction mechanism after learning from animations. The divergence of participants’ mental models for reasoning and visualization could suggest a gap in their mental model consolidation.

Interacting with Three-Dimensional Molecular Structures Using an Augmented Reality Mobile App

“…While they may be able to show users the process of chemical reactions, the lack of user interactivity takes away a crucial aspect of teaching; that is, students would not be able to visualize changes to these models arising from reaction mechanisms . Such cognitive skill is crucial to the understanding of chemistry as a subject …”

“…30 Such cognitive skill is crucial to the understanding of chemistry as a subject. 31 Learning Nucleophilic Addition in CM1121: Organic Chemistry I This project NuPOV ("Nucleophile's Point of View") aimed to utilize AR technology to assist in teaching chemistry concepts to students at the university level. NuPOV was piloted in the freshman course Organic Chemistry I (course code CM1121).…”

The Shrewd Guess: Can a Software System Assist Students in Hypothesis-Driven Learning for Organic Chemistry?

“…15,16 Recent studies have shown that the use of animations help students to move to a more dynamic, and expert, view of reactions. 17 The Mechanisms app by Alchemie ("the App") was developed as a touch-screen software interface to enable students to make sense of the EPF of organic chemistry through experimentation. 18 In the App, students investigate reactions by moving electrons to make and break bonds, to which the App responds immediately using graphical and audio feedback.…”

“…The question becomes how best to help students understand the EPF reasoning of organic chemistry and move beyond memorizing a procedure to explaining a process. − Research has shown that novice learners in organic chemistry focus on surface features when presented with an organic reaction, while experts “see” deeper concepts during each step of a mechanistic pathway. , Recent studies have shown that the use of animations help students to move to a more dynamic, and expert, view of reactions . The Mechanisms app by Alchemie (“the App”) was developed as a touch-screen software interface to enable students to make sense of the EPF of organic chemistry through experimentation .…”

The Mechanisms App: Electron-Pushing Formalism as a Software System

“…15,16 Recent studies have shown that the use of animations help students to move to a this more dynamic, and expert view, of reactions. 17 The Mechanisms app, by Alchemie, was developed to allow students to experiment and "play" with the electrons and bonds of organic chemistry to make sense of the EPF in a game-like experience. 4,18 The original hypothesis that grounded the app's development was inspired by Jerome Bruner's theory of constructivism, and that if students could interact with and get immediate feedback from a software system that presented EPF on a touchscreen, they would be more likely to reason through the mechanisms of organic chemistry.…”