In defense of programming for physics and math teachers

In response to a comment I made on his blog, Mark Guzdial wrote

I am complete agreement that computing should really be taught within teachers’ disciplines, such as math or physics. Computing is a literacy. We write and do mathematics in science. We should also do computing in science.

Current constraints make that hard to get to.

• Why should mathematics or teachers want to use computing? It’s harder (in the sense, that it’s something new to learn/use). And it doesn’t help them with their job. Remember the posts I did on Danny Caballero’s dissertation? Computing does lead to mathematics and physics learning, but different from what currently gets tested on standardized tests. Why should people who make up those tests change? To draw more people into computing? Recall how much luck we had getting CS into the new science education frameworks.
• Who would pay for it? We can get Google to pay for more high school teachers to learn CS — that leads to more computer scientists that they might hire. We can get NSF’s CISE directorate to pay for CS10K — that leads to more CS workers and researchers. Who pays for math and physics teachers to learn computing, especially when learning computing doesn’t help them with their jobs?
• Finally, in most states, computer science is classified as a business topic. Here in Georgia, the Department of Education did announce that only business teachers could teach computer science. The No Child Left Behind (NCLB) Act requires teachers to be “high qualified” in a subject to teach it. If CS is classified as business, then it makes sense (to administrators that don’t understand CS) that only business teachers are highly qualified to teach it. Barbara Ericson fought hard to get that changed, since some of our best CS teachers are former math and science teachers (who date back before CS became classified as business). I don’t know if, in other states, math and physics teachers are disallowed from teaching CS.

It’s a big, complicated, and not always rational system.

That the system is big and irrational is not news to anyone, and the Georgia Department of Education may be about as silly as Departments of Education get.  I have no idea how to fix dysfunctional government bureaucracies, though, so I won’t comment further on that point.

But I disagree on a couple of things:

• Learning to use programming effectively can help physics and math teachers do their jobs better.
• Companies like Google and federal agencies like NSF will pay for teachers to learn computational methods, not just for straight CS teachers.

For the first point, I’m going to have an uphill battle to convince Mark, because he has a carefully done research study that Danny Caballero did for his PhD on his side, and I don’t have 4 years of my life to spend working full time on the question.

I read Mark’s posts about Caballero’s dissertation, I even wrote about them when the posts first came out (and I started another draft post, but abandoned it).  I agree that Caballero’s results are not encouraging, but I don’t believe that a single experiment at 2 sites decides the issue for all time. Caballero showed that a couple of mechanics courses that taught physics using Matter and Interactions did not spend enough time on the concepts of the Force Concepts Inventory (a small but important subset of the concepts of a first physics course), and so students did not learn as much on those topics as in a traditional class. He also showed that students made typical programming errors that reflected poor understanding of both physics and programming, and that students had less favorable attitudes toward computational modeling at the end of the course than at the beginning. The programming errors Caballero found were typical of the errors seen after a first programming course also—if we can’t teach students to avoid those errors when the entire course is focused on programming, it is not surprising that a physics course in which programming is a small add-on also produced students who can’t program well.

Caballero’s thesis study was pretty convincing that those implementations of the intro physics course using computational approaches were not very successful at teaching the concepts of the Force Concepts Inventory. I’m not convinced that the problems are inherent to using computational approaches to teach physics though—just that these courses had not yet been optimized.  It is indeed possible that Mark’s conclusion (computing doesn’t help teach physics or math) is true, but I think that is too big a generalization from Caballero’s results.

Note that an earlier paper on which Caballero was an author showed that the M&I students showed better gains than students in a traditional course on a BEMA test (Electricity and Magnetism, rather than the mechanics topics of the FCI). So even Caballero’s results are not as uniformly negative as Guzdial paints them.

Personally, I liked the Matter and Interactions book, and I think that its approach helped me and my son learn physics better than we otherwise would have, but we’re hardly the typical audience for a first calculus-based physics course, so I don’t want to generalize too much from our experience either—Caballero’s results (positive and negative) are from 1000s of typical students, not 2 very unusual ones.

There are currently teachers in both physics and math looking at programming as a way both to motivate students and to teach physics and math better.  The spread of the ideas in the community is slow, because the teachers are getting little support, either from fellow math and physics teachers or from the computer science community.  People like Mark say “some of our best CS teachers are former math and science teachers”, but also say “it doesn’t help them with their job.”

Teaching physics and math teachers to program can help them do their jobs better—even if they don’t teach programming to students! There are other ways that programming helps them—for example, Matt Greenwolfe spent a lot of time programming Scribbler 2 robots to be better physics lab tools than the usual constant-velocity carts. Other physics teachers are doing simulations, writing video analysis programs (I contributed a little to Doug Brown’s Tracker program), improving data logging and analysis programs, and so forth.  A lot of math teachers are using GeoGebra to make interactive geometry applets (and, more rarely, to have students do some programming in GeoGebra).

As for my second point, there are already many corporate and federal programs to try various ways of improving STEM teaching (the CS portion of that is actually tiny).  To convince them to spend some of that money on teaching math and physics teachers to program, we may need some better use cases than the intro mechanics courses that Caballero studied—or we may just need to re-examine those courses after the instructors have done some optimization based on the feedback from Caballero’s study.