Wednesday, November 14, 2007

PftM2: "Mr. Physics Teacher, tear down this wall!"

In the old days, you had to pass chemistry and Algebra 2 before signing up for physics. Those prerequisites considerably narrowed the potential population of physics students. And the big secret? It turns out you can teach a perfectly good physics class to students who have not passed chemistry or Algebra 2. For a first-year physics course, there's no reason for either of those prerequisites. Let them go!

Will you end up with some "less-qualified" students in your classes? Yes. But accept the challenge and work your craft. You are fortunate enough to teach physics, so teach physics! (And rejoice!)

I don't encourage Honors Physics. I like a "big tent" in my Physics 1 course. Heterogeniety rules! I strongly recommend heterogeneous lab groups. Email me for details on how to make that happen.

Make it possible for all students to succeed. Not all students will succeed, mind you. You cannot have complete control over that. Without the barricades in place, you'll have students who don't intend to be scientists or engineers. And that's OK. Working your craft as a physics teacher means you'll have to guide those literature, arts, and athletic types to success in your class. They won't all follow, but success has to be accessable.

A wise vice principal once told me, "Not all baby sea turtles make it to the ocean." But let students choose their path in your course. Lay out the options. Make them "doable," and let students decide with their actions. You might worry this will water down the rigor of your course. I can say that I get some really bright students at my school and if even the smartest among them was ever bored in my first-year class or felt unchallenged, they never told me.

What am I suggesting, specifically?

Don't put all the weight of the grade on test and/or exam scores. Allow for the fact that some of the ideas of physics require time to settle in. Let students review tests after the fact. (I use a technique called "Test Correction Journal." Topic for another post some day.) Then give them more questions of "old" material on future tests. In EdSpeak, that's called "spiraling." Whatever it's called, it allows time for material to settle, and engenders the idea that "old" material is still important. As the semester progresses, unit tests look more and more like mini-final exams. And that's OK.

Don't grade homework for correctness. Credit for homework is tricky. Students want it and teachers don't want to give it. My analogy is to ask student athletes about practice. "Before the match on game day," I ask, "how many points do they put on the scoreboard in recognition of the practice you did all week?" There are clever ways to encourage the completion of homework. I use a technique called "The System" which is a general method to encourage good academic behaviors and discourage the bad.

Don't forget to have some fun from time to time. Throw eggs. Do groovy demos. Show Roadrunner cartoons. Laugh. You're teaching the grooviest subject on campus; there's gotta be some fun in there somewhere.

The biggest challenge for any physics teacher is simply to remember how hard the material was the first time. A tall order, especially for those of us who have had significant coursework and years of experience. Doubly challenging if physics came easy to you. (Happily, I was never "cursed" in that way.)

If you've got Algebra 2 and/or chemistry barriers in front of your physics course, you're keeping a lot of good students out of your course. And denying them an excellent high school physics experience. Don't do it!


Anonymous said...

A true breathe of fresh air! Thanks. You have the same feeling oabout your class that I have about mine ... physics is the coolest class on campus. Rejoice indeed!


dt said...

Dean, Thanks for reinforcing teaching verses test taking 101.
Can you share more about engaging your students with homework? I find that the classroom part goes well for me, but each year more and more students do not even attempt homework...



Canton Mommy said...

Hey, just found your blog and it is "groovy". Enjoying your Book of Phyz info - hooray! Agree with your views here, agree with dt - less homework is coming in. Even when credited for completeness not corectness. I'll be a regular now - and get the textbooks YOU want!

Marjorie said...

Great work.

Tim Lund said...

Dean, I am in full agreement of your ideas on keeping physics accessible. My classes are growing, and I have gone from 2 classes up to a full load of 5 in my school. The "watering down" aspect is somewhat true, but I use physics to bring students who are weak in math to new levels of appreciation and understanding. And students who are "mature" can always come to me for extras. Physics teachers need to keep the subject from withering away.

sharad said...

very good work

Frank said...

Very good! I'm a retired physics teacher who tried to take the algebra out of problem solving by arranging equations in the form of triangles (F=mgh) in compartments or rectangles (F[centripetal force)=mv<2>/r). Place a finger over the term you're solving for, and the position of the other terms gives the equation to solve the problem. Always make them include the units when solving the problem, and have them do the math on them first to see that they get the correct unit in their answer. I made this an attention getter by having T-shirts made(in school colors)with the various figures printed upside down on the front(so you can read them)and rightside up(so the student seated behind can read them). When worn on campus,they also got some other students interested in physics. I don't believe students should have to memorize equations, just know how and when to use them. By the way, college profs allowed them to wear them when taking their tests, and knew where they came from!