|Above is an example of the layout style I'm applying to|
problem sets. Every problem will require both verbal
AND mathematical response. See this link for a
google docs example:
projectile problem on google docs
Traditionally in my algebra-based AP-level physics course, I've assigned about two homework problems per night. When I began teaching AP, I selected these problems from the textbook. All textbooks seem to label their end-of-chapter problems by difficulty: level I or * means easy, level III or *** means hard. In every major textbook, the problems at the middle level of difficulty tended to be approximately on target for AP.
Now, there's much more to learning college-level physics than solving end-of-chapter problems. Although textbooks are trying to improve, still their problems are heavily calculational. Conceptual questions requiring verbal responses are shunted off into another section, rather than integrated into every problem. That's not how an AP exam is structured.
An AP free response question will have 3-5 lettered parts. Some of these parts will likely require calculation; some parts will require explanation. It is rare nowadays that a single free response item does not include BOTH verbal and mathematical sections. I want to mimic this style in my own nightly assignments -- partially as a tool to prepare for an AP-style exam, but primarily because I think it good pedagogy to integrate verbal and mathematical questions.
When I began teaching AP, I scoured my textbook for good, level II, end-of-chapter problems. The assignment would be stated as, "Do chapter 10 problems 29 and 64." After I had taught the course for a few years, I began to add my own additional parts to the textbook problems, such as "... for problem 64, also describe as you would to a non-physicist the size of the boat." And in the past few years, I've re-written most problems entirely to phrase them the way I want.
This summer, I've revised my assignments again for the express purpose of integrating verbal and mathematical responses into every problem. I've typeset the assignments in MS Word, so that each night's assignment takes up a single page, front-and-back, with room for the answers. You can check out this projectile problem on google docs as an example of the format and style of an assignment.
Why the room for answers after each part? For a long time now I've observed that students will tend to use whatever space you provide for problem solving -- no more, no less. If they use their own lined notebook paper, problems are crammed into as few lines as possible. When I've provided full sheets of blank paper, they use most of the full sheet -- great, but sometimes I get an essay when I wanted a two-sentence response. My hope is that I will get my class in the habit of giving just the right depth of response by subtly showing them the space that should be filled.
For those of you who are in their first few years of physics teaching, I would suggest you file this post away for future reference. It takes enough time at first to figure out how to solve and explain the problems; don't worry about whether the problems are perfectly phrased, or well-typeset. Just get the students in the habit of communicating their solutions.
But if you've been teaching a while, and if you're wondering how to make your assignments shorter yet more effective, I think this style is worth a try. Make students write verbal responses on every problem, so they see that physics is about so much more than getting the right number.