Assessment as a Teaching Tool

Tests Are Key to Success

Tests and grades are important to students, and so tests are perhaps the physics teacher's most important teaching tool. Used appropriately, tests serve the dual purpose of making students aware of their own conceptual difficulties while preparing them for the structure, format, and rigor of the AP Exam. Some notes on how I use assessments in my class:

There's no need to test every unit. Valuable class time is better used with demonstrations, labs, and discussion. I schedule test dates no more than once per marking period, then construct the test to reflect whatever material has been covered, regardless of whether I'm behind or ahead of schedule. Students and parents do not fail to point out that such infrequent testing makes each test “high stakes.” Good! This way, students prepare better for each test. And if they don't handle the pressure well, better to find out early in the year with a chance to recover and learn from the experience. The AP Exam itself is an even higher stakes, one-shot opportunity.

Make all tests cumulative. The AP Exam tests an entire year's worth of material, so why give students an excuse to forget previous topics? It's amazing how much more comfortable students are during April review when testing has been cumulative throughout the year.

Give tests in AP style. Practice exams should go on all year, not just in April. I use almost exclusively authentic AP multiple-choice and free-response questions on every test. I grade the tests based on an AP rubric; in fact, my students initially receive not a letter grade but a 1-5 score. Grading tests on the AP scale has turned out to be one of the most important elements of my course. Students know where they stand; they see that 60 to 70 percent is not the failing score they feared, but is actually quite strong. Students are willing to put in more work on their own when they see exactly what is necessary to earn each score; they feel like they are working for their own benefit rather than to satisfy a teacher's arbitrary requirements. (The raw score is curved to a letter grade based on their test corrections—see below.)

Make students learn from their mistakes. I assign “test corrections” in which students earn half credit for a thorough explanation of each multiple-choice item they missed the first time. I also occasionally reassign a free-response item later as a quiz, on which I've changed the situation slightly or asked additional conceptual questions. Since these test corrections contribute to test grades, they're taken quite seriously.

Quizzes have a variety of purposes:

• If I've had to move on to a new topic, but there's still trouble with the previous topic, I will often announce a quiz: “I know some of you are still struggling with Lenz's law, which we covered last week. Friday's quiz will ask you to find the direction of induced current in four different situations; you will have only two minutes to finish all four.”
• At my previous school, students habitually sauntered in after the bell rang. I began giving a daily two-question, multiple-choice quiz. The quiz provided a focal point for discussion at the beginning of class, often leading smoothly into the day's demonstration. From a time management standpoint, though, the quiz effectively gave me several extra minutes of productive time per class, since only students who were in their seats at the bell were allowed to take the quiz. It only took a couple of days until a pattern of on-time arrival set in.
• Even if they're worth few or no points, quizzes can provide a quick and accurate check of understanding. A short but well-designed quiz, say with two conceptual multiple-choice questions or one short-answer question, can be more useful as review than even half an hour of class discussion.

Authored by

Greg Jacobs
Woodberry Forest School
Woodberry, Virginia