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"Spherical Cow"
The title will make sense shortly...
I gave 'reading quizzes' (algebra based Physics I and II) that are due before each lecture- these are 3 short-answer questions designed to identify student misconceptions prior to the lecture so that I can directly address any conceptual difficulties as they arise. Recently, when asked "why does a wire get thinner as it is stretched?", nearly every student gave a highly complicated response in terms of forces and stresses (when all I was looking for was conservation of mass/volume). I was genuinely perplexed, and when I asked the class why they gave such a complicated response, one student replied "well, I didn't think that the simple answer could possibly be correct, since nothing in this class is simple", which got a lot of knowing giggles from the other students.
So I trudged into Jearl's office and we started talking about the 'intellectual baggage' students bring into class, and he mentioned that many students see the teacher as a magician who regularly turns one object into another- for example, turning a cow into a sphere. When he said that, I realized he was absolutely right- the next day I started the class by asking if I acted like a magician and got a lot of nods. I spent a recitation period trying to explain why I do that (abstraction of essential concepts, etc), but didn't get much of a response. The students have a lot of trouble relating real things to the idealized/abstracted models I create. Even when I have them step through the process: for example relating the free-body diagram of a car going around a turn to what happens when they are driving around a turn and hit a patch of ice, they can't make that leap. There's a persistent disconnect between what they know happens from experience and what they think happens "in physics world".
I was just wondering if any of you all are aware of this (teacher as magician), if you have consciously tried to address this, or any other relevant ideas.
The title will make sense shortly...
I gave 'reading quizzes' (algebra based Physics I and II) that are due before each lecture- these are 3 short-answer questions designed to identify student misconceptions prior to the lecture so that I can directly address any conceptual difficulties as they arise. Recently, when asked "why does a wire get thinner as it is stretched?", nearly every student gave a highly complicated response in terms of forces and stresses (when all I was looking for was conservation of mass/volume). I was genuinely perplexed, and when I asked the class why they gave such a complicated response, one student replied "well, I didn't think that the simple answer could possibly be correct, since nothing in this class is simple", which got a lot of knowing giggles from the other students.
So I trudged into Jearl's office and we started talking about the 'intellectual baggage' students bring into class, and he mentioned that many students see the teacher as a magician who regularly turns one object into another- for example, turning a cow into a sphere. When he said that, I realized he was absolutely right- the next day I started the class by asking if I acted like a magician and got a lot of nods. I spent a recitation period trying to explain why I do that (abstraction of essential concepts, etc), but didn't get much of a response. The students have a lot of trouble relating real things to the idealized/abstracted models I create. Even when I have them step through the process: for example relating the free-body diagram of a car going around a turn to what happens when they are driving around a turn and hit a patch of ice, they can't make that leap. There's a persistent disconnect between what they know happens from experience and what they think happens "in physics world".
I was just wondering if any of you all are aware of this (teacher as magician), if you have consciously tried to address this, or any other relevant ideas.