In your next teaching practicum:

Identify a connection between something in the world that you are trying to explain and a theory that is used to explain that.

In my next teaching practicum, I will be trying to explain how geologists have inferred the structure of the Earth’s interior using the theory that seismic waves will reflect and refract at boundaries between layers of varying composition and density. This is a difficult concept to explain since we cannot see the interior of the Earth so students have to accept this theory as proof that the interior of the Earth is highly differentiated.

How are you helping your students make that connection?

Reflection is a common concept that is generally well understood so the focus in explaining this theory will be on refraction. A common example of refraction is how a pencil “breaks” when it is placed in water because the light is refracting as it travels from air to water. This is a good example to use because students will have likely seen this effect in their daily lives.

This theory will also be explained using P- and S-wave shadow zones. Students will be shown images of where on Earth P- and S-waves would be detected if an earthquake that originates at point X could generate seismic waves that could travel through the entire Earth. The connection here is not as strong because we cannot model that S-waves can’t travel through liquids, which is the evidence used to explain the S-wave shadow zone. If they accept this they can then understand that the outer core must be a liquid to create the size of the observed S-wave shadow zone.

Does your process help your students be able to make connections beyond that particular exercise? How does it do that? and if not, what can you do to help them be able to do that?

I found this question difficult to answer since I’m only giving one lecture in the course and will not be interacting with the students after that, so I think it’s hard to say if they will make connections with this theory after my lecture. I think the use of a real-world example (the pencil in water) is memorable and I hope that students will think of that example when they have to apply refraction in other situations. Also, if students decide to continue studying geology, the concept of a differentiated Earth will be referred to time and time again and they will learn countless more examples that support this theory. Specific to my lecture, I will also be talking about the Earth’s magnetic field, which can only occur because the Earth is differentiated. This is a second example that requires the Earth to be differentiated and will hopefully allow students to make connections between seismic refraction and the Earth’s magnetic field.

In your next Observation:

If the instructor is talking about a concrete experience or phenomenon, are they making connections between that concrete experience and a theory in their discipline? If yes, how?

Rhy was explaining how the rock record of the Palaeozoic changed through time with the change in marine life. This is a real phenomenon because geologists have noted real changes in the rock record and they have attributed that to the amount of hard parts that marine animals possessed at that time. Rhy did a good job of connecting this idea to the real world by using humans as an example of how organisms would be preserved in the rock record based on the compositions of various hard parts in our bodies.

Does the activity they are using to do either of the above cases help the students make connections beyond the particular application they having students experience?

The activity was designed to get students to make connections between the composition, fossil content, and age of a hypothetical rock. Students were split into small groups that fell into four different age ranges based on the row they were sitting in in the classroom, with the oldest rocks at the front and the youngest in the back. They had to use their clickers to share information about their rock with the class. While other groups were providing information to the class, the students were expected to make notes so that by the end of the activity they would have a picture of the entire Palaeozoic. I thought using clickers was a really great way to share information in a large class. It would obviously be better if students could form new groups and share their information with their new group members but with 80+ students it would likely be a logistical nightmare. Once students saw the results of all the data from the 4 groups, they could see how the rock record evolved through time and how the composition of the rocks was dependant on the types of fossils they contained. I think this idea has broader applications because it demonstrates how a rock can be “dissected” to provide a wealth of information about extinct organisms, paleo-geology and even paleo-climate. It also gives students insight into how palaeontologists were able to recreate the biology of extinct organisms using the rock record.