In Preparing for AP Physics 1: establishing the habit of writing Greg Jacobs writes
I’m in the infant stages of planning my AP Physics 1 course. The big trick is going to be establishing my students’ ability and willingness to write their reasoning, to get them to focus on communication rather than on getting a correct numerical answer. Once it’s clear that they are not taking a math course—once they see that the solution to a problem looks much more like what they’ve done in biology or economics than in calculus—I think the students will be able to move along quickly and enthusiastically through the material.
Students must get comfortable with calculation. However—as was correctly pointed out to me at the AP consultant meeting in April—if we start the course with lots of pure calculation, students will think that getting the answer is the holy grail of physics problems. If instead we begin the course demanding description, explanation, and all sorts of prose, students may become accepting of the idea that a numerical answer is merely the result of careful reasoning.
If this change in AP Physics actually works (something I’m always skeptical about in any curriculum reform, particularly at the high school level), it may help engineering students in college. Engineers do far more writing than most professions, with far less training at doing it.
I don’t think that a prompt that just says “In a clear, coherent, paragraph-length explanation, describe how you would figure out …” is going to do the trick, though. If they could already write clear, coherent paragraphs about how they would figure something out, then they would not need the curriculum change—they might not even need a physics class at the level of Physics 1.
I’m struggling with this problem in my applied circuits course, in which I require weekly design reports for the circuits they design and build. The students are staying in lab until they finish the designs and demo them, so they are clearly capable of doing the work (though not always as quickly as they should). But only a few students can explain their computations for the design parameters (like gain, corner frequency, and component values) clearly—others put down any nonsense that has a few of the right buzzwords in it.
The top students have gotten better at their explanations as a result of feedback, but the bottom students are still often producing word salad. Although there is some indication of a general writing problem (lack of topic sentences, poor grammar, and misused vocabulary), the problem is most pronounced when they are trying to explain how they selected component values. The more steps that there are in the underlying math, the more jumbled their explanations, even if the problem is just a chain of multiplications.
From time to time, I’ve suspected that the students don’t produce coherent sentences about how they computed something may not have actually done the computation, but “borrowed” the result. This is not an explanation I believe in strongly, though, as the students have been (mostly) coming up with different solutions to the design tasks, so there isn’t simple copying going on. I’ve also seen the design process the students use, as they have been doing their pre-lab work in lab (instead of at home), so I hear them discussing the problems. They do ask each other not just what answer they got, but how to get the answers, so they are trying to learn the method.
In looking at the pre-lab homeworks that were turned in on Monday I realized what part of the problem is—the students keep absolutely awful design notes. What the students turned in on Monday (even the top students) was mostly incomprehensible scribbling of numbers, with no indication where the numbers come from or what they were attempting to compute. Half an hour after writing down the notes, I’m pretty sure that they could not reconstruct their reasoning—hence the often magical methods in their design reports, where they copy numbers out of their notes (some of which are correct), but can’t put together a coherent chain of reasoning that leads to those numbers. On the long multi-step computations needed to figure out what gain an amplifier needs, they can usually do each step (though often needing coaching on one or two of the steps, either by me or by one of the better students in the course), but they don’t record the meaning of each step or even what the sequence of steps is, and the “answer-getting” mentality causes them to flush the process from their minds as soon as they have a number.
I’ve seen a lot of lab exercises for other courses that try to scaffold the process by providing worksheets that give the step-by-step process and have the students fill it out as they go along. I don’t think that this is helpful though, as it encourages students to solve one step at a time and then forget about it—the scaffold prevents the students from exercising the very skill that I most need them to learn. Showing them worked examples, as I have done in class, doesn’t seem to help much either—they can follow along as I break the problem down with them, and think they understand, but then not be able to do the same thing themselves. Again, the scaffolding prevents them from exercising the skill I most need them to learn—identifying problems and them into subproblems.
For next year, I’m probably going to have to come up with some exercises which get students to organize their thoughts external to their heads. So far, the only thing I’ve thought of is to have them create a fill-in-the-blank worksheet for each lab (like an income tax form), and turn in the blank worksheet and try filling out each other’s worksheets. If they get in the habit of writing down the steps as steps, it may help them be able to reconstruct their work when they convert it into full sentences for the final reports. It may be too late for me to do anything formal this year (only 2.5 weeks left), but I’ll suggest it to the students anyway.
The advice I’d give to Greg Jacobs is to leave the “clear, coherent paragraph” until later in the quarter—get them to create worksheets first.
I’d welcome any suggestions from my blog readers on ways that I can get students to learn to organize their thoughts in a way that they can present them coherently to others. Block diagrams alone don’t seem to be enough, and vague things like “mind maps” are likely to do more harm than good.