For juniors and seniors, my school offers only two levels of physics that don't require a prerequisite: AP physics B and General Physics. I will have a number of students taking General Physics as a graduation requirement, so this course must be accessible to folks of all academic abilities. My approach to General Physics has been to teach mechanics, waves, circuits, and optics to the AP-B standard. The goal is that if my students could take the AP physics B exam, but strip out all of the topics that we haven't covered, they'd all pass. That makes for a slow-moving but powerful course. On my February exam, I do give a long set of AP free response questions, on which my students perform easily to passing standard.
I've already detailed the free response questions, most of which are at the AP level, that will be on this spring's final exam. But I want to give a set of multiple choice questions as well. Most of the multiple choice questions available in the physics universe are at the AP level. Since I have not spent any time this year with the General class practicing the correct approach to multiple choice questions, and since they have not had multiple choice questions on any other test, and since I want the multiple choice to HELP their performance rather than to serve as an additional challenge... I need some straightforward multiple choice.
Enter the National Science League.
The NSL is a shamelessly commercial organization which sells science (and math!) contests at all levels from elementary to high school. Their business plan is sound -- create straightforward multiple choice tests annually, promote the tests as a national "contest," and get schools nationwide to open their wallets. In return for a sum of money, the school gets the test itself, some certificates and medals, and recognition on the NSL website on which schools are ranked in each subject by the performance of their top 10 students.
I personally have no trouble with the commercialism. The NSL is filling an open economic niche. From a competitive standpoint, the "contest" is worthless: the 40-question multiple choice physics test is written such that any AP student who misses even one should be flogged. Commercially, though, that makes a lot of sense... more teachers will be willing to give the NSL contest, and thus pay money for it, if they know that their students will feel successful. Nothing wrong with that.
I use the NSL physics contest not as a contest, but as a set of multiple choice questions uniquely suited to my general physics class. By coincidence, the topics of the NSL questions align nicely with my own choices: mainly mechanics; some waves, optics, and circuits. There are always a few thermodynamics or electrostatics questions that I have to cut out, but usually at least 35 of the 40 questions are right in the General Physics wheelhouse.
As part of my final exam this year, I will give the 2010 NSL. As an added benefit, I have a built-in review packet: for practice leading up to the final exam, I have given out a previous year's NSL. My students are consistently missing no more than 3-6 questions out of nearly 40.