Molecular Workbench – a successful lesson on diffusion and osmosis

For this weeks lesson, I decided to take a look at Molecular Workbench. Molecular workbench is a open-source software that allows students to run simulations of scientific phenomena at the macro scale level all the way down to the subatomic scale. It is also a modelling tool that allows users to design their own simulations and experiments and create simulation based curriculum materials.

For this week’s reading, I chose to read the article by Friedrichsen and Pallant (2007). This article describes a series of lessons on diffusion and osmosis. They use the 5E instructional model, which consists of the following 5 phases: engagement, exploration, explanation, elaboration and evaluation. Molecular workbench was used in the explanation phase. The lesson started with student making predictions on what would happen to a skinned potato if it was submerged in three different environments; water, 0.9% NaCl solution, and 10% NaCl. During the exploration phase, the student made observations on what happened to the potatoes. Then they are given a chance to come up with an experiment that could help explain the observed phenomenon. This is done in small groups and the group decides on the experimental method based on the supplies that are available (which includes dialysis tubing, a semi-permeable membrane). In the explanation phase, the students try to make sense of the data collected during the exploration phase. Molecular workbench is used at this stage to help students develop molecular-level explanations for their findings.

Molecular workbench allows students to visualize phenomena that cannot be seen by the naked eye. Unlike static images, students can see the constant motion of molecules as well as their interactions, which results in diffusion and osmosis. The interactive nature of Molecular workbench also allows students to manipulate variables and see the outcome, which is helpful in understanding the interplay between the molecules and the environment. These cognitive affordances of the program aid in developing an understanding of these complex phenomena. In addition, during this lesson, Molecular workbench is a group activity, which allows students to not only interact with the program but interact with one another to discuss observations, and make sense of the changes that occur when they manipulate certain parameters. This discourse is important in developing understanding.

Molecular workbench activity was followed by reflection and revision of their original explanations of the potato experiment to include molecular and cellular level representations. What I really liked about this lessons was that it models the way the scientific community acts. Instead of the teacher critiquing each group’s explanation, a peer review process was performed, and students were given opportunities to clarify or revise explanations based on feedback from their peers. Finally in the elaboration phase, students are asked to apply their knowledge of osmosis to new contexts to strengthen their conceptual understanding.

I believe this is a very successful lesson on diffusion and osmosis. As noted by Srinivasan et al. (2006), many novices view software simulation as “fake”, and strongly value “real” experiences over such simulations. In this lesson of diffusion and osmosis, the authors introduced the topic using something that was very relatable to students, presented them with an opportunity to participate in a “real” experience through a hands-on experiment, but also tied this to phenomena at the cellular level using software simulation. I think this is a great example of how information visualization software can be used successfully in eduction. Visualization software is great, but unless these visualizations are tied to something students can relate to, it may be just as abstract to students as the concepts that it is trying to demonstrate.

References

Friedrichsen, P. M., & Pallant, A. (2007). French fries, dialysis tubing & computer models: teaching diffusion & osmosis through inquiry & modeling. The American Biology Teacher. http://doi.org/10.1662/0002-7685(2007)69[22:FFDTCM]2.0.CO;2

Srinivasan, S., Pérez, L. C., Palmer, R. D., Brooks, D. W., Wilson, K., & Fowler, D. (2006). Reality versus Simulation. J Sci Educ Technol, 15(2), 137–141. http://doi.org/10.1007/s10956-006-9007-5

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