Lemke writes in “Analyzing Verbal Data” about the concept of retrospective recontextualisation

“Discourse forms do not, in and of themselves, “have” meanings; rather they have a range of potential meanings. Words, phrases, sentences are tools that we deploy in complex contexts to make more specific meanings, to narrow the potential range of possible meanings down to those reasonably or typically consistent with the rest of the context. Even in context, at a moment, an utterance or phrase may not have a completely definite meaning. It may still express a range of possible meanings, differently interpretable by different participants or readers. This is very often the case at the point where it occurs. The context needed to specify its meaning very often at least partly follows its occurrence. So it may seem to have a more definite meaning retrospectively than it has instantaneously. In fact, depending on what follows, its meaning, as participants react to it, can be changed radically by what follows (retrospective recontextualisation).”

I thought about Lemke recently while reading Alex Barr’s post* about productive prior knowledge. In that post, he describes a discussion he had concerning the common misconception about the moon’s phases (i.e., the earth’s shadow is cast on the moon), and how you can think about that misconception in terms of kernels of productive knowledge (e.g., the moon itself blocks light from getting to the back half).

Lemke argues in the above passage that the meaning given to any student utterance happens in interaction, in part based on what proceeds the utterance itself. I’m imagining this in the context of teacher re-voicing. Specifically, I was imagining three different revoicings that might occur after a student makes a statement like, “The phases are casued by the earth’s shadow falling over the moon,” and how they might, retrospectively, change the meaning of the student utterance. Here’s the gist of several possible re-voicing.

“It sounds like you are trying to draw our attention to an important idea we should consider in explaining the moon’s phases–light from the sun can be blocked by objects that get in the way. “

“It sounds like you are saying that there must be something blocking sunlight from getting to certain parts of moon. And you’re proposing that one thing that could be doing that blocking is the earth.”

“So your idea is that if the earth were to block some of the light from getting to the moon, then we’d see changes to how much of the moon is lit.”

“It sounds like you are saying the

Its interesting to me how these different voicings may (or may not) change the meaning of the student idea. The first one (in my mind) attempts to re-voice the idea by focusing on what the teachers know to be a kernel of truth, downplaying subtly what is not true. The second one attempts to re-voice the idea as a particular case of a more general principle, perhaps opening up the idea, giving it room to breath and be connected to other ideas. The third one re-voices the idea as a conditional proposition–one that the teacher knows to be true about lunar eclipses. A more straight forward re-voicing such as, “It sounds like you are saying that the phases of the moon happen when the earth blocks light from getting to the moon,” seems to narrowly frame the idea, sort of pinning it down, giving it no where to go. The re-voicing doesn’t help to put the idea in a broader context or to highlight any parts of it as being more or less significant.

One reason I’ve been thinking about this so much is because next semester, one of the goals for teaching of physics is to develop skills at facilitating classroom discussion. One of the discourse “practices” we will focus on is “re-voice and toss“. There are of course, lots of reasons for re-voicing, but I feel like I’m circling around something here… hopefully more to write on this later.

* Alex is a burgeoning physics education researcher at the University of Texas at Austin, who you should say hello to, get to know, and keep your eye on. *