Tasker GROUP

Tasker GROUP

Tasker Group
Using visualization to understand chemistry

We develop and evaluate different kinds of visualizations to make sense of the terminology, symbolism and concepts in chemistry at all levels.

Meet the group
Sharing our work for peer review and implementation

Our work is published in peer-reviewed academic journals, and journals for professional science educators at all levels.

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our News
Activities and events in our research group at Purdue

Noteworthy developments, achievements, and fun in the group

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Our Research Projects
Project design, development, & evaluation

We address significant problems in chemistry education where visualization can play an important role in the solution.

Putting research into teaching practice

Multimedia resources, websites and keynote presentations

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Our Research IMpacts teaching practice

An essential goal of all our research is to improve student learning outcomes through refining evidence-informed teaching practice.

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Meet our Core and extended research group

The core group presently involves three graduate students, with a postdoc researcher and an animator to join us soon. We also have graduate students in Gabriella Weaver's group working with us, and undergraduate students helping out.

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Group News

Roy presents a keynote at the Chicago Science Symposium
February 10, 2016 7:00 PM

On 5 February 2016 Roy presented a keynote and follow-up workshop at the Chicago Symposium Series ...

Roy promotes VisChem in Singapore
December 1, 2016 11:20 PM

Roy presents keynote, workshop and panel discussion on VisChem at Singapore Chemistry Education Conference

Christmas Time at Purdue
December 20, 2015 3:00 AM

We celebrated our first Christmas holiday together as a group. Before we ...

"You need to imagine the molecular world to really understand chemistry"

visualization example 1:
WE CAN classify organic molecules into levels

A central focus of organic chemistry is the conversion of carbon-based molecules into other molecules. Functional groups in these molecules can be classified into Levels 1, 2, 3 or 4 based on whether there are 1, 2, 3 or 4 bonds between a particular carbon atom and more electronegative atoms (O, N, P, S, or a halogen, X). This scheme was developed by James Keeler and Peter Wothers at Cambridge University.

Converting molecules in one level to a higher level involves OXIDATION (decreasing the electron density on a C atom), and to a lower one involves REDUCTION (increasing the electron density on a C atom). Conversions within a level simply involves swapping one electronegative atom with another. In this way you can see whether you need an oxidizing agent, reducing agent, or a non-redox reagent for a specific conversion.

Visualizations like this can organize lots of ideas into meaningful 'chunks'.



Inside the MOLECULAR world of Sneakers
- flexibility, stretching & BOUNCe -


flexibility without stretching

The long-chain molecules in nylon act like sticky cooked spaghetti, lying on top of one another. The dotted lines are weak bonds (hydrogen bonds) between the molecules. So it's a bit like a zipper, where even though all these bonds are weak, there are so many of them, the molecules can't slide over each other. So nylon does not stretch, but it is flexible.



Here we can see the rubber sole getting compressed, with its long-chain molecules squashed closer together. They can’t slide over one another because of the strong bonds (covalent bonds between sulfur atoms shown in yellow) between the molecules. As the molecules are squeezed together the big bulky groups (hexagonal phenyl groups) hanging off the chains repel one another. This is why rubber is compressible and returns to its original shape.

Why We Do what we do

The chemistry education research literature demonstrates that many student misconceptions are due to an inability to visualize substances and reactions at the molecular level, due mostly to misinterpretations of the meaning of chemical formulas and equations.

We need to help students to develop useful mental models of the molecular world to make sense of chemical concepts like equilibrium, entropy, chemical speciation, and hydrophobicity, and to make conventional symbolism meaningful.

However, we know that we cannot do this by simply showing students complex visualizations, that portray our expert mental models of this world, and then just expect novices to adopt them for understanding chemistry concepts. We use a cognitive learning model to inform how we use visualizations.

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