This is the time of year when physics teachers tend to be approached by hyperconcerned AP students worried about the upcoming exam. "Can you find me more practice problems? I want to do as many as possible so I'm prepared."
The teacher's answer should almost always be "no."
Huh? Um, Greg, why not provide more practice problems? Why shouldn't students be encouraged to study more, especially when it's they who are taking the initiative?
I'll give you two reasons.
For one: It's the quality of preparation that is useful, not the quantity. I've assigned an enormous number of AP practice problems as homework, tests, quizzes, and in-class exercises. For each of these, I've helped students understand what they've done right and wrong, and how to do better on the next exercise. We don't just do a problem and forget about it. I check homework and make students redo problems that they substantially didn't understand. We grade each others' quizzes in class. We do test corrections. In-class exercises lead to discussion, or sometimes experimental verification.
In contrast, handing students a thick pack of review problems encourages the mindset of just getting the answer right, without the deep engagement required when working in conjunction with a formal class.
And a thick pack of review problems can't possibly be useful unless the problems are themselves high quality. I just got an email from a prominent supplier of inferior physics lab equipment saying something like "With the AP exam approaching, try these practice questions for $99!" Stupid, stupid, stupid.
Authentic old AP free response questions with authentic rubrics are available to students through the College Board's official site. The five steps book has an enormous number of questions, each with a thorough solution, not just an answer. These are publicly available to students - and the 5 Steps book costs a fraction of $99.
I've seen some of the material that's peddled by others as AP exam preparation. It's uniformly terrible. Pick up a random other prep book and look at the content and style of questions. The GOOD ones are repackaged AP Physics B material, heavy on the calculation, nowhere near the style and depth of the true AP Physics 1 exam. Folks, there aren't that many people in the country qualified to write AP Physics 1 questions. The vast majority of those are already in the employ of ETS and the College Board.
For two: I refuse to feed the test anxiety beast.
At this point in the school year, with three weeks to go before the AP exam, I'm tapering my AP class. We are winding down, not up, in our preparation. I have a lot of reasons for relaxing my demands in April, but a primary one is to emphasize with my actions that "test anxiety" can be limited by building a positive culture.
We've done the necessary deep practice all throughout the year. I've ensured every day that students have not just done the homework, but they've paid careful attention to it; if they don't, they come in for consultation. For each incorrect answer on a test, my students write a clear correction. We've built the habit that practice doesn't make perfect; perfect practice makes perfect.
By year's end, all of my students know what they can and can't do. They understand their strengths and weaknesses, and how to play to those strengths on the AP exam (because they've done so on eight AP-style practice tests already). They know how to handle the adversity that is sure to come on an exam on which 70% is a top score. They've already done their practice problems on tests and quizzes and homework - that's how they know all of the above.
What message would I be sending, then, if I kept handing ever-larger sets of practice questions in the lead-up to the exam? I'd be destroying the confidence I've struggled so hard to build. There's no need to scare students into studying more.
Top students tend to work themselves into a state right before an exam. Or, they do more and more practice problems as a way to show off to their peers... it's the secular equivalent of the holier-than-thou churchgoer. But we're talking about top students! They don't need to study more. What are they going to do, turn their 5 into a 6? Make them relax, both for their own mental well-being and for the sake of their classmates.
But what about students who will struggle to get a 3? They will do better with a low-key approach, too. Rather than shame them for not knowing everything - which is what we do, like it or not, when we shove a stack of practice problems at them - focus these folks on just a few topics that they can improve upon. They're not going to get a 5 because they studied for days. But, a few judicious hours here and there might well secure that 3.
So, don't encourage more practice. Encourage good, targeted practice in the weeks before the exam. Encourage a relaxed, confident attitude in the days before the exam. When students recognize intellectually and emotionally that AP exam day is just another day at the office, then your class is ready to rock. No extra practice questions required.