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Instructional goals, instincts, and decisions

September 19, 2011

This post is about instructional decisions in my inquiry course, which I am trying to be more explicit about.

If you read my last post, my class has some theories about what light does when it reaches different surfaces. They also have identified some challenging puzzles involving light on surfaces. Their theories are tentative and their puzzles are complex. I’ve decided that it’s my job to help them bridge the gap between some of our theories and some of the phenomena we’d like to explain.

My specific plan of action is based on at least  two notions I’d like to make explicit:

I think my students need some practice “holding a specific theory in mind” and working out its implications. So far, we’ve been doing a very different kind of scientific work–trying to sort through a swamp of our own ideas and experiences to reach some understanding of what’s going on. Along with this work, we’ve been changing our minds a lot, because we keep having new observations or ideas to contend with. To me, it’s about time we start “trying on some ideas” or at least “committing to some ideas just long enough to see where they lead us”.

Conceptually, I also think they need to be nudged toward the vicinity of “source-object-receiver” models. I have been trying to push various groups in this direction during conversations here and there, but so far, no one seems to be concerned with it. Our ideas are about where light goes, and much less with who can see what from where. This is going to be pretty important if we are going to get anywhere with our puzzles, which specifically concern what different observers see.

In summary, my goal is to narrow the gap between theories and puzzles. We have a lot of good theory and very interesting and revealnt puzzles. I also have two instructional instincts: these students need to make contact with a new kind of “scientific practice” (following implications) and a new “conceptual idea” (source, object, receiver). I also have some other goals, which function as constraints. For example, I want to honor and value the class as author’s of ideas and nudge them in directions that at least seem continuous with what we’ve been doing so far.

Anyway, here is my first draft, for what we’ll be doing on Wednesday. They have some predictions to make based on below, some things to discuss, and then we’ll be moving forward with some observations. My final goal for the day will be to pin down some “community rules” for drawing diagrams, and maybe have a conversation about the difference between a sketch (which might get across the gist) and a diagram (which could be used to make a specific prediction). Anyway, what do you think?

2 Comments leave one →
  1. September 20, 2011 3:54 am

    I see where you’re headed — showing the “faces” as positions of people (who might be in the path of some light) seems helpful. There’s something about the perspective of the drawing that’s messing me up — probably will be familiar to your students, but I found myself wondering if it was a top down view or an “elevation”? Is that the top of the table we’re looking at? If so, the flashlight appears to be bolted to the side of it… If not, what’s holding up the black paper? Are the people above the table or behind it? This probably isn’t what you had in mind, but I would have to draw a floor plan of the positions of things before I could start (the idea of “angle of elevation” might also be adding an extra wrinkle).

    The formulation “intuitive prediction” vs “theoretical prediction” is clear to me, and no doubt your students have lots of experience using the word “theory” in the scientific way, but I know that mine would have to focus pretty hard to remember not to use it in the colloquial use (meaning something like “intuition”).

    Something similar happened in my class today — we collectively agreed on a model of atomic structure and tested what it would tell us about some measurements we took. I handed out a sheet with headings for the main ideas we’ve come to consensus about so far, so that everyone would have a place to record what we agreed on in their own words. It also functioned as a checklist of “what does the model say anyway.”

    I found that the students were able to come up with lots of implications, but had a hard time keeping them separate from “what we know from previous experience or we think we learned in a class or read somewhere” (in other words, noticing our assumptions). I think I should have modeled it first, especially because there are some kinds of tentative phrasings that are useful for demonstrating the difference between “the model says this” and “I think this,” But practice seemed to help.

    Cris Tovani advocates a reading comprehension strategy called a “double-entry diary” where a sheet of paper is divided in half vertically. One column is reserved for quotes from the text, the other is for the student’s own thinking. I’ve been experimenting with using Cornell paper as a double-entry diary. I asked students to use one column for what they read or saw or what the model says, and the other for their own thinking — including inferences based on the model, things they remember seeing/reading/learning in the past, and questions they have. Interestingly, my students are getting rapidly better at distinguishing between their thinking and others’, but only in print. The double-entry recording also has resulted in more self-assessment of their thinking than I’m used to (comments like “The two parts of this thought are contradictory”), I guess because their thinking is easier to find than if it was mixed in with everything else.

    My students are jazzed by making their own Cornell paper — in case it’s of use to you, here’s an online generator. Looking forward to reports of how this goes.

  2. September 20, 2011 12:11 pm


    Thanks for the detailed feedback. I think this issue of “the model says this” and ” think this” is so crucial. That’s my main goal here. I really like the idea of the two column paper. This weekend I collected notebooks–some students were really good at “reporting what happened in class and what others said and did” and others were really good at “getting their thinking and ideas down, with their reactions and responses to others’ thinking”, but only a few were good at both. Modeling this for them and giving them a structure to do that within could really help.

    I imagine I won’t actually give the above “worksheet” to students. It’s a draft of my thinking, and I’ll probably set up a scenario at the front of the room. I’ll Mark three places to stand away from a table, and use a clamp and stand to hold the black paper. Then I’ll bring up the theories from Monday and write questions on the board.

    The issue of theory vs intuition, I *think* will be OK, but you never know. Yesterday we talked a lot about theories that describe some “ideal” situation. The Back group has a theory about “ideal black paper” absorbing all the light, even though we know that most black things don’t absorb everything. The Door group has a theory that matte surfaces “koosh bounce” the light in all directions, and mirrors “direct bounce” at equal angles.

    The Door group found that shiny surfaces do a of little both, so they are like a combination of two ideal things (mirrors and matte surfaces). To me, it’s a really interesting question: can our class model most real objects (in terms of how light interacts with them) as some combination of ideal black, ideal white, and ideal mirror?

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