Wednesday, January 02, 2013

How Not To Teach Physics?

This is an interesting article written by former U. of Ottawa professor Denis Rancourt (you may want to read a bit of his history with his former university). Certainly, article that appeared on this Dissident Voice webpage consistently challenge the establishments and the established notion. I have zero issues with that. However, I question the validity of many conclusions, especially when it is only backed by anecdotal evidence. And just because someone questioned the conventional way of doing stuff does not make him/her immune from being equally questioned for the conclusion he/she is drawing.

Rancourt wrote on how ineffective the standard method of teaching physics is at imparting physics knowledge to students. Certainly, there have been plenty of studies to indicate that such dull methods of teaching is not every effective. He then described how he did it is own way and how, in his opinion (and the opinion of his TA), it showed an improvement.

I told the students to close their books and not read them, unless they thought they might find something of interest in there that they wanted to know. I told them they could look anywhere they wanted and ask anyone questions to find what they wanted.

I told them that first we needed to figure out what was worth knowing, and what it means to know.
I got blank stares. They worried about how they would be graded in such a system. They wondered what I really meant and what did I want them to do. But they gave me a chance and, luckily, I didn’t know what I was doing, so it was quite authentic.

So I said: “Let’s see. There must be every day things that we want to know, that we can understand…? Things we are curious about?”

They couldn’t find any. Some of them said they had a lot of work to do in their other classes so they did not want me to be too demanding. Many shared that view. But as the conversation continued and as it became clear that, well, it was a conversation; they relaxed. But they still could not think of anything they wanted to know, beyond the latest homework in the other courses. Sad really.

So I said: “Why is the sky blue?” “No really, how does that work?”

Well many of them had heard something about that in high school so we started a class-wide discussion about how and why the sky is blue. And for every answer that did not quite work, we were able to find a flaw in the answer, or a dead-end, where the word answer was not really explaining anything beyond “something something”.

I told them that it maybe had something to do with why the evening sky can be red and also asked why clouds are white, when they are not red.

So this led us to what is light…? Now you can spend a lot of focused time asking yourself what light is if you want to know why the sky is blue. So I discovered… I helped them see, through questions, what it was to truly know or understand something versus just repeat the words… that they could search and explore and critique themselves. So they did.

And we had a final examination. And, honestly, it was like no final examination I had ever seen before. It was the opposite of depressing and fun to grade. It was full of intelligence and independent thought and evidence of significant research. I had a sense that the students had understood things, could explain them, and owned their knowledge.

I went back to the previous year’s examinations and saw a huge difference. I lent the two piles of examinations to the TA and she concurred that, yes, there was a significant qualitative improvement that could not be denied.

Now know that I was not comparing “bad” teaching to “anything would be better than that”. I was considered one of the best traditional method teachers, by the usual standards. So I was comparing certified bad teaching to something much better.
Now, there's a number of issues here that were not tackled:

1. Many physicists today were taught using the "conventional" methods. I was one of them. While one can argue that these may not have been the best technique, one cannot argue that WE, as a group, didn't learn any physics from them. In fact, I will vehemently argue that my E&M instructor was one of the best teacher that I've ever had and left his permanent imprint on me on how I learn things in physics. He taught things in a conventional means, but he was damn good at it. So then, is the problem here the philosophy of teaching, or the EXECUTION of that philosophy, i.e. how such conventional teaching is presented? Was Rancourt's ineffectiveness  in making the student learned early on a problem of the philosophy of teaching, or was it because he simply was not a good teacher executing that philosophy or methodology? I'm not saying he isn't, but this is something we don't know.

2. How effective is his new "technique"? Sure, anecdotally, he could claim that the exam results were better. But this is not how we arrive at things in science. Educational research requires quite a number of sampling, testing, and controlled groups for comparison. One simply can't claim one has discovered something better simply via such anecdotal evidence.

3. Note that other countries, especially Asian countries such as Korea, Singapore, and China, have continually produced masses of students that have tested higher in math and science. As far as I can tell, their teaching and learning techniques are still heavily "conventional" and not approaching anywhere near what Rancourt is doing. So why are these kids able to learn and understand physics?

I fully understand the desire to do things differently. After all, I've written extensively on how I would revamp the undergraduate intro physics labs to fulfill various goals. However, until that is properly tested, I would not make any kinds of claim of its effectiveness, because I'll just be doing what I've criticized a lot of people have done - relying solely on anecdotal evidence before proper, scientific and more-verified evidence are available. And people who dissent should not be quick to dissent by lowering their standards of what can be accepted to be valid.



joernwilms said...

I agree with most of your points, except your argument that the high results of some asian countries in tests show that the traditional method works. There are quite a few educational papers that show that Asian students taught in the traditional "cramming" way, are not good at physics concepts, even though they are very good at solving the physics questions that are usually asked in entrance exams and other exams testing undergraduate level knowledge of physics. Perhaps the best article about this is Kim, Pak, 2002, Students do not overcome conceptual difficulties
after solving 1000 traditional problems, Am J Phys 70(7), 759-765

Douglas Natelson said...

Having read Rancourt's post, it's really not possible to tell what kind of class this was intended to be. From his description of the course, it sounds like it was a conceptual physics class - I find it very hard to believe that first-year students taking a class consisting entirely of discussion of interesting everyday phenomena could actually solve problems in the end. Yes, physical intuition and insight are important, but there's a big difference between conceptual knowledge and being able to compute actual physics. That's why people who read popular, vernacular discussions of quantum mechanics differ from those who actually can calculate dipole matrix elements, etc.

Steve W said...

Most of the "unconventional" teaching styles I've seen are not innovative ways of teaching physical concepts, but rather tricks to get the students to be mentally present and invested in their own education. While these tricks may produce some improvement in junior students who've yet to develop good study habits, I highly doubt they'd have impact on more mature students. Nothing can really replace the structure and mathematical rigour of a well-taught course. It's my opinion, as a student, that a good professor can balance both flavour and rigour. I would have HATED D.R.'s course for lack of organization.

I think it's clear that the conventional styles do not appeal much to students who are not the "self-learning" type that D.R. describes. But, the purpose of a degree in physics is to train students for a career that REQUIRES self-learning. The philosophical debate is whether we should subtract from actual course content in order to teach students such proper study habits. I personally feel that these issues are better handled in tutorials and labs where there is more opportunity for interaction between students and the instructor.

It's worth noting also that there are some students who are perfectly capable of doing well, but are not interested in putting forth the effort (though for good reason). I'm saying this as the lead TA for a first year chemistry tutorial, in which we challenge students to work together and think about the physical content of the topics in relation to everyday chemistry. The students who are most resistive to discussion are those in non-chemistry related majors who only have to take the course to satisfy a degree requirement. I've been told straightforwardly by a student, "I'm in applied health science; I know I could spend more time on chemistry, but I choose to focus my time on more relevant courses." Professors need to realize this is OKAY. Sometimes the students who are motivated to "self-learn" (usually the majors in the topic) are the most important to reach because they will actually apply the knowledge in the future.

In summary, I think the challenge of "getting students to understand the physical content of the topic" is too often confused with "getting students to actually do work". Unconventional teaching methods claim to solve the first problem, but are really solving the second. While they may have merit, if the real problem is properly identified, then conventional solutions can be developed that don't sacrifice actual rigour that the "better" students need.