Modeling Earth Science-Instructional Plan Implementation Reflection

            “A scientific model is a representation of a system that includes important parts of that system to help us think about and test ideas of the phenomena” (Kenyon, Schwarz, & Hug). I chose to use a hard-boiled egg to represent Earth which was a very simple model to use. Students knew right away that the egg was a good representation of the Earth simply because of the yolk (the core), and the shell (the crust).  They had learned about this in January at the beginning of the Astronomy unit.  Overall the lesson went very well, and students were engaged during the lesson while using the model Earth to explore the tectonic plates.  For me, this was very much a structured inquiry lesson, but instead of using an experiment, students used a model.  They made observations and were able to share their explanations with others. The goals of the lesson were met and students were able to name the plate boundaries easier than at the beginning of the lesson. They all successfully drew the three types of plate boundaries and named them, transform was the most difficult to remember.  They could also explain what types of physical features they create on the Earth’s surface.  Some of the problems that I had were with students not cracking the egg enough and cracking it too much that the yolk came out.  I think that I should have made it clearer, perhaps to provide a visual of how to crack the egg and apply pressure on the outside, but I was afraid that I would give them too much information.  During the partner activity, students were able to describe to each other and point out on the egg’s crust the various boundaries that they could see. Most students drew diagrams in their notebooks and wrote down observations while they were completing the model activity.  Another challenge that my students had were drawing the diagrams and writing down their observations. Perhaps if I had provided them with an observation sheet, and was more clear about what types of observations, and various drawn egg silhouettes so they would have something to start with, students would have been more successful.  Again, I was afraid to limit the amount of observations they wrote down, nor their creativity.  I think sometimes, if the activity is too open for middle school students, then the activity and assessment provides me with little evidence of their learning.  The model activity was very straightforward, however before we used the egg, students thought that the plates were all the same when plates come together.  They thought that all convergent plates formed mountains, until they had the chance to see subduction zones (areas where one plate went under the other).  They were also not aware that oceanic crust was more dense than continental crust, but thinner.  “The two types of crust vary because they are made up of different kinds of rock” (Tillery, Enger, & Ross, 2008, p. 342). The variation on the model where they added continents (tape pieces) was really good in that it allowed them to see how continental crust when thicker, it resists breaking more than the oceanic crust.  I believe the knowledge they gained from using the model, was far more than if they had just read the book, or just watched a film.  As one student said, “This was a great model because we could feel the tectonic plates moving in our hands."

            Overall, using the visual model for investigating plate tectonics was a great way for helping my diverse population of 7^th grade students, learn about the plate boundaries of the Earth and areas where disturbances form Earthquakes. Students learned the three types of plate boundaries, the two types of crust on Earth, and how the oceanic and continental crusts interact with each other to create the various physical features on Earth. One thing that I may change next time would be to give them more time to investigate the model and to make their observations and also perhaps to use an animation of the tectonic plate movement for each form of boundary. I feel that may be what was missing for some of my students so they had something to compare to.  I would most likely use this lesson again next year for helping students to understand the Earth’s plates as well as the other models that I used to help them understand Earth and Earth’s waters. Perhaps I could even provide students with choices of how they learn about the tectonic plates such as simulators, websites, or the model. They could also choose to represent their learning in other ways rather than taking notes, or drawing diagrams.  “Choice provides students opportunities to try different modalities for experiencing an idea or expressing what they know” (Dotger & Causton-Theoharis, 2010).  

Here is a SlideShare version of the PowerPoint I used with my 7th grade students. 

Plate tectonics

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References

Dotger, S. & Causton-Theoharis, J. (2010). Differentiation through choice: Using a think-tac-toe

for science content. Science Scope, 33(6), 18–23.

Kenyon, L., Schwarz, C., & Hug, B. (2008). The benefits of scientific modeling. Science &

Children, 46(2), 40–44.  

Tillery, B., Enger, E., Ross, F., (2008). Integrated Science. (4^th Ed.). New York, NY:

McGrw-Hill.