Nothing works to remind me how young eighth graders really are better than pulling out play-doh or clay for an activity. Within seconds students are making sculptures that range from silly to incredible (and, let's be honest, sometimes inappropriate, they are eighth graders after all).
I like to tap into this natural enthusiasm to kick off a unit whenever possible. This information processing unit is a natural place to introduce students to the many forms that science models can take and have them begin to identify/evaluate the strengths and weaknesses of different models.
This opening lesson will have students creating two simple models of the brain that serve completely different purposes. One model will show different regions of the brain while the other provides an example of the weight and consistency of the brain. Students compare these two models as they become familiar with the uses and limitations of modeling in science.
I begin the lesson by going through the PowerPoint What Are Scientific Models? This informs students about the basics of scientific models, provides the instructions for the day's task, and contains the analysis questions students answer after constructing their model.
Whenever I plan on having students compare 2 different concepts/creations, I have the right half of the class focus on one and the left half focus on the other. This is the format I follow for this activity. All tables on the right side will create model 1 and the tables on the left will create model 2.
Model 1 Instructions:
Materials: different colored clay or play-doh, toothpics, paper, scissors, tape
(To make your own play-doh follow this recipe, it is the best I have ever tried.)
The groups making this model are instructed to create a model using the play-doh that identifies/labels the different regions of the brain. I allow students to make any other design decisions as what they create is not as important as the analysis they complete following the model making. For students who need more assistance in finding information (ELL or special education students) I like this link because it still allows for student choice as they determine if their model has only the 5 regions labeled or if they include the additional information pictured.
Example of model:
When their model is complete, students answer the following questions in their science journal (second to last slide on scientific models PowerPoint)
List all the pros of your model
List all of the cons of your model
To assist students I provide them with Student Directions Brain Model 1 so they can work as independently as possible.
Model 2 Instructions:
Combine all of the ingredients in the ziplock bag and mix thoroughly. It should weigh about 3 lbs. (1.35 kg.) and have the consistency of a real brain. If you choose, you could have these groups research the weight and consistency of the human brain either prior to or following the creation of the model.
When students are done they answer the same questions listed above. To assist students I provide them with Student Directions Brain Model 2.
As each side finished with their model, have them switch sides so they can examine the other model. Have students answer the following questions (last slide of the PowerPoint).
As students clean up, I show them this short video that clarifies some common misconceptions about the brain.
TIP: Please preview this video prior to using it to ensure that it meets the norms and expectations for appropriate communication in your classroom and school. Also, note that the last 30 seconds (about) are dedicated to the source of funding for this episode, and a plug for more of this series. You can always stop it.