Learning science involves explaining observable phenomena, such as stickiness, magnetism, and heat transfer, through imagination and modelling of their underpinning invisible causes – in these cases, molecular interactions, force fields, and energy changes.
Visualization of such imperceptible phenomena is the key to making meaning from the abstract scientific shorthand and language that too often alienate novices.
Only when they have useful visual mental models of these invisible worlds can novices appreciate the enormous power of mathematics to generalize from the specific.
The three thinking levels are illustrated below for the chemical reaction that occurs when silver nitrate solution is added to solid copper.
In this reaction dendritic silver crystals growing on the surface of copper metal can be perceived directly at the observable level. Why are silver atoms forming at the ends of the silver crystals?
At the molecular level we can imagine electron cloud transfer from the copper lattice along the silver atoms in a crystal. Hydrated silver ions in the solution near the silver surface gain this electron cloud, converting them to silver atoms. The atoms adhere to the growing cluster of silver atoms in the crystal.
The chemical equation summarizes the reactants, products and reacting ratio in a reaction at the symbolic level. This tells you nothing about how the reaction happens.
Educators need to prime the perception filter, minimize the cognitive load, and facilitate elaborate linking to prior learning.
Using visualization to teach science should be informed by the latest cognitive science research on the factors determining how the brain perceives, processes, stores and retrieves audiovisual information.
Our group includes graduate students, post-docs, undergraduate research students, research assistants, animators, and visiting academics, all doing interesting projects addressing significant problems where visualization has a role in the solution.
The VisChem project continues to involve producing NEW animations that depict molecular level structures and processes for a deeper understanding of chemistry concepts. We will extend the present collection to portray additional inorganic and organic reactions at the molecular level, and develop and evaluate new learning designs to present them.
The high cognitive demand of dynamic, complex visualizations has been shown to be a potential impediment to their effectiveness as learning objects. We will develop new ways to present animations to reduce their cognitive load based on recommendations in the cognitive science literature. We have access to excellent eye- tracking facilities at Purdue to assist in this project.
Odyssey (by Wavefunction Inc.) uses a molecular dynamics force field engine capable of simulating multi-molecular systems to give an unrivalled visualization of homogeneous solutions and heterogeneous mixtures. We want to develop and evaluate student learning activities that give students the opportunity to construct their own simulations in guided inquiry molecular-level activities.
Thermodynamics is considered a difficult topic in chemistry. We want to develop visualizations that help students to understand the mathematical relationships between the key quantities.
Many chemical processes and systems in biochemistry are complex and difficult to explain. Based on experience with producing resources for Stryer’s Biochemistry 6th Ed textbook we are interested in developing and evaluating resources that visualize biochemical cycles (e.g., citric acid cycle) and signalling systems with feedback.
Reaction mechanisms in organic chemistry are often portrayed with arrow symbolism that can appear mysterious to novices. Based on experience with producing resources for Vollhardt’s Organic Chemistry textbook we are interested in developing and evaluating resources that visualize organic reaction mechanisms.