Friday, February 15, 2013

the white hole

I gave a test to my Regents Physics students this week. After the test as he left the classroom, a pupil of mine said he thought it was a good test. At first I was struck by this- a student telling me I wrote a good test? Awesome! Maybe it was a good test... Then I started thinking about it. Why did he think it was a good test? Because it was easy? Because he thought it was appropriate? Because it played to his strengths?

I wasn't sure. The student in question is bright, but not the most focused. He also has trouble with details- writing down starting equations, units, etc. The other day we were practicing and I mentioned that he had neglected some units. He asked me why they're needed, I explained, and then he decided it wasn't worth his time, even if the Regents exam will penalize him heavily for their omission. The test opened with difficult multiple choice, a short essay, and then some problems to solve. Nothing terrible, but many students made it harder than it needed to be. To illustrate this, let's consider two problems. First:



They said that the horizontal throw of the rock wouldn't make any sort of difference. Most mentioned a demo I had done in class with two pennies and a ruler, and the majority got full credit. I was pleased- it seemed like they understood.

Later in the test, the following problem appeared: 

The results were much worse than I had expected. 60% of the students used the horizontal velocity as the initial velocity in the vertical direction, and then got bogged down solving the resulting quadratic. It was painful to see. Was it a bad question? I don't know- what do you think? I thought it was good until the results came back.

On a bigger scale, this got me wondering it the test I administered was a good one. Is any test good? Would a more conceptual test be better? Would such a test prepare them for the state exam at the end of the year?

I've been using Standards-Based Grading with my AP students, but not with my Regents Physics class. Testing the waters, so to speak. I love SBG, but the workload is tremendous. Would it be better? Undoubtedly. Would it do me in? Perhaps. I hope to redesign my Regents class for next year from the ground up, and I'd love to incorporate SBG. We'll see how that plays out- lots of it depends on the school administration.

By the way, the student who complimented me on the test passed with a 70. I see three possibilities:

1) he thought it was a fair test but didn't know the material as well as he should have and complimented the test despite this
2) he was over-confident and thought he'd done better than he actually did
3) he was just messing with me.

I don't think it was the third one. I'm a reasonable judge of character and he was being sincere.

On a final note, in class yesterday we were talking about energy, and a student asked about black holes and what would happen when you fell through one. We talked about how it would rip you apart, and then he said "but when you come out on the other side through the white hole, it would put you back together again, right? It basically made my day, I laughed so hard I was almost crying. Apparently there is a vein in my forehead that starts to pulse when I'm either laughing or angry, and the kids all noticed it today. Sweet- there goes my poker game, and now I've just told the world about my tell!