Thursday, March 19, 2009

Constructive science in the classroom

"Imagination is more important than knowledge." --- Albert Einstein
Science should be taught as a verb, not only as a noun. Doing science is a compelling and effective way to learn. It is through the process of exploration, creation, and invention that theories are applied, ideas are tested, and knowledge is synthesized and upgraded. This post showcases some interesting simulations recently created by students using the Molecular Workbench software and proves the feasibility of using the constructionist approach to teach science more effectively.

The image on the left is a screenshot of a student's simulation about how a ball that has a density lower than that of water keeps afloat in a bucket being filled up by rain. The dynamic simulation shows how buoyancy works with an amicable setup of clouds, rain, a ball, and a bucket. The simulation and the note made by the student (not presented here due to privacy issues) clearly show that the student had learned not only the modeling tool but also the science during the construction process, because the simulation produces the emergent behavior exactly intended and explained by the student.

The second image is a screenshot of a student's simulation about the gas laws. Designing something that violates a physics law is often very motivational to students. Students are inspired to use their creativity to come up with every imaginable possibility of violation. This student designed a subtle situation in which all atoms in one container move only in the direction perpendicular to the piston and atoms in another container move in both the perpendicular and the parallel direction with an initial setup that guarantees the equipartition of the kinetic energy in each direction. The simulation shows that the volume of the gas in the right container is approximately half of that of the gas in the left container. Is the Ideal Gas Law broken? We leave this question to you.

The third image is a screenshot of a simulation of a salt crystal and water a student created using the 3D Molecular Simulator. It shows that the student knew what a crystal structure is and how dissolving occurs. Considering the complexity of constructing a 3D model (over a 2D one), this student's work is quite impressive. The fourth image is a screenshot of a simulation of photosynthesis created by another student, which shows the student's understanding of this complex biological process and her efforts in modeling it.

A common challenge in using a general-purpose modeling tool in the classroom is that it may take students longer time than teachers are willing to spend in the classroom to make something pertinent to the learning goals. Tempted by the versatility of the tool, some students even tend to "drift" away from the learning goals. To help students focus on learning science, the Molecular Workbench software permits instructors to design scaffolded construction activities while engaging students to build simulations. This is a unique and important feature of the software that will facilitate the wide adoption of this pedagogy.

From the point of view of assessment, the richness of information expressed in these simulations has much to offer to research and evaluation about using computer simulations in the classroom. As a Chinese proverb says: "A picture is worth a thousand words," a simulation may be worth much more than a thousand words for the assessment of student learning. Ultimately, the most reliable and relevant assessment of educational simulations should use simulations themselves as the data sources. The only way to make this assessment work is to engage students to make their own simulations.


Ji Shen said...

The three models mentioned in the blog were created by Jason LeBroad (collecting rain droplets), Robert Chapman (3D salt dissolving), and Jessica Maddox (photosynthesis) who took my technology class. It took them 2 weeks (6 class hours of instruction + time outside class) to finish the project. Most of my students adapted some existing models from the MW library. I believe that adapting existing model is much more feasible than creating new models from scratch in a classroom setting. On the other hand, a series of very small changes or variations could lead to a totally new creation (Shen & Confrey, 2007).

In the class I observed how students learned not only the modeling environment but also content knowledge (concrete examples to be added). Or during the modeling processes students expressed their misconceptions in a way they didn’t notice.

In these practices, I've notices several challenges that students face. These could be the very reasons prevent classroom implementation of modeling practices with an interface like MW. Future design, I suggest, should take these challenges into consideration.

1. A lack of understanding of how molecules/particles behave (e.g., molecular level forces) may pose a big barrier. The knowledge required to make a model work easily exceeds a high school level. When a model doesn’t work (e.g., explode), it is probably because students don’t understand what they are “asking” the molecules to do. Programs such as Phun, Crayon Physics require little prior knowledge other than common sense. However, MW can address a much wider range of topics.
2. The detailed user manual is conceivably very helpful for devoted modelers. But it requires students a high level of commitment. Rarely, students bother to read the manual. Phun has a community of modelers who share their Phun models, Youtube instructions, and new ideas on an online forum. MW needs a more open, interactive environment for participants.
3. The user interface is very complicated. Students with little experience with MW are easily lost with the many tools in the modeling environment. This could be alleviated by using several pedagogical strategies (detailed instruction from teacher, adapting existing models, sharing models with peers). MW may consider to create different interfaces to suit different levels of modelers (e.g., a lite version vs a full version).

Gregory Louie said...

Hi Charles,

Thanks for starting a blog. I hope it catches on and reaches more teachers. I'll give it a tweet from my Twitter account.

I use MW often in my classroom as part of a learning sequence for teaching the molecular basis of life.

I'm hoping for the completion of WISE 3.0 so I can deliver the sequence in a web-based guide through MW and other non-MW media.

All the best to you and your team at Concord.