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2012 February 29

Modeling Instruction

Filed under: home school — gasstationwithoutpumps @ 18:32
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In my reading of physics teacher blogs, one pedagogic buzzword comes up over and over “Modeling Instruction”. I got some pointers to papers in a comment by Jane Jackson, when I asked for references about peer instruction (a somewhat broader buzzword).

Unfortunately, I’ve found most of the papers on modeling instruction to be rather long, wordy, and not very useful for telling me what the technique was.  (They are heavy on measuring that the technique is useful, without actually saying what the technique is.)  I found Hake’s comments on the ap-physics mailing list and his web pages so aggressive and unhelpful that I could not bring myself to read more than one of his papers.  I got some useful information (about a page or two worth) out of the 32-page
Malcolm Wells, David Hestenes, and Gregg Swackhamer
A Modeling Method for high school physics instruction
Am. J. Phys. 63 (7), July 1995, 606-619.

The content can be pretty well summarized by their “box 2”:

The Modeling Method aims to correct many weaknesses of the traditional lecture-demonstration method, including the fragmentation of knowledge, student passivity, and the persistence of naive beliefs about the physical world.

Coherent instructional objectives

  • To engage students in understanding the physical world by constructing and using scientific models to describe, to explain, to predict, to design and control physical phenomena.
  • To provide students with basic conceptual tools for modeling physical objects and processes, especially mathematical, graphical and diagrammatic representations.
  • To familiarize students with a small set of basic models as the content core of physics.
  • To develop insight into the structure of scientific knowledge by examining how models fit into theories.
  • To show how scientific knowledge is validated by engaging students in evaluating scientific models through comparison with empirical data.
  • To develop skill in all aspects of modeling as the procedural core of scientific knowledge.

Student-centered instructional design

  • Instruction is organized into modeling cycles which engage students in all phases of model development, evaluation and application in concrete situations—thus promoting an integrated understanding of modeling processes and acquisition of coordinated modeling skills.
  • The teacher sets the stage for student activities, typically with a demonstration and class discussion to establish common understanding of a question to be asked of nature. Then, in small groups, students collaborate in planning and conducting experiments to answer or clarify the question.
  • Students are required to present and justify their conclusions in oral and/or written form, including a formulation of models for the phenomena in question and evaluation of the models by comparison with data.
  • Technical terms and representational tools are introduced by the teacher as they are needed to sharpen models, facilitate modeling activities and improve the quality of discourse.
  • The teacher is prepared with a definite agenda for student progress and guides student inquiry and discussion in that direction with “Socratic” questioning and remarks.
  • The teacher is equipped with a taxonomy of typical student misconceptions to be addressed as students are induced to articulate, analyze and justify their personal beliefs.

That was all very well, but still rather vague. There was an example running for several pages, but it didn’t help me much in seeing what characterized “modeling instruction”. Perhaps others would find it more informative.

I finally got a more satisfying answer from the ap-physics mailing list where I was directed to a series of blog posts: Salt The Oats: FIU Modeling Workshop.  These posts by Scott Thomas are reflections on a workshop that he took in June and July of 2011.  He offers the disclaimer

… if this interests you, please go to the workshop, don’t just rely on me.  Even after only one day I can tell that my recount will mean nothing for you without you attending.

Since I’m only planning on teaching physics once (and am almost halfway through), I’m unlikely to attend a two-week workshop, so reading Scott’s notes are about as close as I’m going to get.  His descriptions are fairly detailed, and I think I have a better idea of what modeling instruction involves from his description than from any of the more formal papers I’ve been pointed to.  (I’m not knocking the papers—they provide the evidence that the technique works—they just don’t provide enough information about the technique to come close to duplicating it.)

It is already too late for me to use some of the “modeling instruction” principles.  The students I have do read the book and understand the math, so much of the effort of getting the students to develop their own models would not be productive—they’d jump immediately to the “right” model and just verify that their data fits it well enough.

I am trying (now) to get the two students to work together to set up and solve problems and to design labs (rather than my designing the labs)—we’ll see how that goes.  And I am trying to get them to use a more standardized layout for problem setup: drawing the free-body diagram, listing the initial and final state, writing out the appropriate fundamental equations.  I don’t know how much it is helping, as the students were already pretty high performing and good at setting up the right model without much fumbling around.  As we get to more complex problems, though, they may need a more disciplined approach, so I’ll try to provide the appropriate framework of generic questions and general-purpose tools (like free-body diagrams).

At least I was, from the beginning, using an approach that minimized memorization and re-derived things as much as possible from a few key formulas. I’ve always hated memorization (which is part of why I was a math major as an undergrad—almost no memory work). The textbook I’m using, Matter and Interactions, supports that approach pretty well—I believe that the authors were trying to get a bit of the modeling instruction flavor into their text (though the videos of Ruth Chabay’s lectures are very much a traditional lecture-demo style).

I am thinking about how much of the “modeling instruction” approach could be adapted for teaching introductory programming to biologists (my most challenging pedagogic task for next year). High-school and first-year college physics has only a few key concepts (the “models” of modeling instruction), and most of the effort in physics classes is in getting students to learn to do problem solving using that handful of models.  Are there equivalent key concepts in introductory programming?  Or are the problems beginning programmers have more like those of beginning biologists: too many unrelated factoids?  I think that programming is more like physics than like biology, with relatively few key concepts, applied to solve a wide range of problems, but that might be an unfamiliar way of thinking for the biology students who will be in the class.  So if I can find an approach that has the strengths of modeling instruction but applied to programming rather than physics, I’ll have a chance at getting most of the students to an acceptable level of programming skill.


  1. I’ve seen the instructional materials (when reviewing books for a HS physics curriculum). The materials I saw were developed at Arizona: Unfortunately all of it seems like its behind a paywall. But, the curriculum was developed with NSF funding, and I wonder if they would give you access to it — if you asked in the right way.

    I think they’re concerned about the curriculum being used without training (in addition to the more commercial concerns about having the opportunity to monetize through their workshops and to pursue continued NSF funding). They want teachers to gain access to the materials after attending the workshops, but potentially you could have it to review, consider from a college educator point of view?

    I think the materials (I looked at Chemistry & Physics) were good. They were slow — for example, there’s a unit around measuring falling objects that your son’s elementary school projects seem to have surpassed. A teacher-ed person might think that your son was regurgitating equations, but from your descriptions I’m convinced, for what that means, that his equations reflect an understanding of the underlying models. So, I’m not sure how useful it would be.

    I do think they try to do what you describe: to try to grow the science out of a few fundamental concepts. Physics lends itself to that style, and the question of whether those concepts are taught through experimental manipulation or math descriptions isn’t relevant to me, in my opinion, seems only to matter if the student doesn’t *understand* the math as a model description. If one does (and I know plenty of people who see math that way), the direction doesn’t seem to matter as much, in my opinion (i.e. model/math -> experiment or expeirment -> model/math).

    In chemistry, the models are the 1/2 complete ones that we remember from high school, approximations with exceptions. They bother me, but they may be a useful teaching tool, anyway.

    I don’t know if Arizona has biology materials yet, but in biology, the concepts would be organizing principals, and they do help in understanding biology, though the principals aren’t broad enough to tie everything in biology together.

    Comment by zb — 2012 March 1 @ 07:10 | Reply

  2. principles, though organizing principals might help (or hinder), too.

    Comment by zb — 2012 March 1 @ 07:16 | Reply

  3. I went back and read Jackson’s comments, and saw that she’s one of the people behind the ASU program. I think one of the points that comes out in that comment thread and the post that precedes it is the relevance of “struggling” with the material, to make sense of it in understanding. Your original post referred to Mazur’s request to students to read chapters; Jackson responds by talking about classroom concepts and interaction; I wonder if quizzing might have similar value (requesting the students to do some pre-test that engages them with the material) or whether working out the math has the same effect.

    Comment by zb — 2012 March 1 @ 09:11 | Reply

    • Jackson’s comments implied that there was a lot more to Mazur’s success than “just” getting the students to engage with the material before class. (As others have commented, finding ways to actually get college students to do reading before class would make an enormous difference.) I looked over some of the papers that she pointed to, and while they show impressive gains for the modeling instruction approach, they do not identify which aspects of the approach are crucial to success. (Maybe it was in some of the papers—I burned out on reading the papers before getting to them all.)

      I’m curious about what aspects are most important, because it would be nice to try applying them to fields other than physics—particularly to beginning programming, which does not appear to be one of the fields that they’ve been trying to adapt the methods to at ASU. (At any rate only mentions physical science, physics, chemistry, and biology.)

      Certainly reading quizzes (even just one-question ones) are a popular technique for encouraging students to do the reading before class. I doubt that they get the weaker students to really engage with the material, though—the students just resign themselves to failing the quizzes.

      Comment by gasstationwithoutpumps — 2012 March 1 @ 09:22 | Reply

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