Lunk I-RISE Congress Presentation

My talk was titled "Negotiating a Shared Meaning of Potential Energy." Obviously, a short week is not enough time to turn out an analysis of any sort, rather purpose of this talk was to foster a discussion of an extended conversation the teachers had about potential energy.

Before getting to this, however, my presentation took a brief detour through my background, as were the norms that were established by other presenters.

While at NCSU, my graduate research involved developing a framework for understanding students' computational modeling practices. We had gathered a plethora of videos of introductory physics students completing computational models within laboaratory environments. The particular models that they were tasked with building covered many phenomena (orbital motion, Rutherford scattering, etc...) however the students started with pre-written bodies of code that were missing important elements of a physical model (force laws and momentum updates, for example.)

The students had many fantastic conversations about the physics and about problem solutions during their lab. Often times, however, these discussions lacked any evidence of computational thinking, dispite the program being the immediate representation of the model.

In order to describe these data, I extended a framework of Epistemic Games, Resources, and Framing to the domain of computational modeling.  

Obviously, the context of the data that I gathered as a graduate student has very little overlap with the Energy Project: I looked at freshmen/sophomore college students, EP involves in-service elementary and middle school teachers; I focused on momentum-centric representations of phenomena, EP focuses on energy; I looked at computational modeling, EP looks at generating qualitative representations.

Because of this, I did not come into this project with any particular research agenda. Rather than expicitly looking for discussions about energy dissipaiton, say, or the use of representations, I simply had to look for teacher interactions which piqued my interest and use those to spark discussion with my fellow I-RISE schollars.

The conversation that excited me the most was an extended, class wide discussion on potential energy. Thoughout this discussion, the teachers worked to negotiate a shared meaning for what this particular form of energy represents and how it relates to other elements of the ongoing conversations (i.e. kinetic energy, height above the ground, interaction with the Earth).

Before discussing this particular interaction, let me first discripe the instructional context. Earlier in the day, the teachers observed Lane fire a "whirlybird" into the air. The teachers then developed "Energy Cube" representations of two of the steps during whilybird flight. At this point, Lane, Lezlie, and Ana brought all groups out into the lobby to discuss their repective representations. It was during this conversation that the topic of potential energy came to the fore front.

Regretably, due to my untimely computer crash, I do not have the clip to post on this blog, however the above slide contains the title for the full video. My clip started approximately 20 minutes in, when the thrid group presents their energy cube representation.

During this discussion I observed three ways that the teachers used to describe potential energy: On in which energy is stored in an object, one in which kinetic energy dissipates into thermal energy "revealing" a potential energy that was always present, and one in which potential energy turns into kinetic energy (and vice-versa).

With the benefit of retrospection, I should note that my use of the word "model" in these slides was imprecise and, unfortunately, introduced unneeded confusion in the resulting conversation. I should have steered the discussion to focus on the language and gestures that the teachers were using as they negotiated a shared meaning. We can certainly project a conceptual model onto what the teachers' particular turns of phrase evoke in our own expert minds, however the word "model" does imply a conceptual coherence in the teachers' understanding which may not exist.

When describing potential energy as energy being stored, the teachers would often use the metaphor of a rubber band of a spring. They would gesture by miming the act of stretching something. This is not an unproductive way of thinking about energy, however it does suggest the possibility that the teachers were introducing an extra attribute to energy: that it could be stored or it could be active (Similar to Hunter's description of teachers cheating at E.T.). One could imagine that to these teachers, potential energy was not a new form of energy, but was a state of activation for an existing form.

The second way of describing potential energy included a description of energy dissipation, specifically that kinetic energy would eventually turn into thermal energy (say, through friction with the air). This description included the mention that all of the kinetic energy turned into thermal, thus revealing a potential energy that was always there. This description is suggestive of a conflation between energy and the the gravitational force, however the teachers did maintain the language of conservation between the kinetic energy and the thermal energy.

The "standard conceptual model" really should have been titled the "transformative description." Teachers taking this stance described kinetic energy turning into potential energy. This description includes gestures of height and aligns the most closely with how experts (in my experience) talk about potential energy.

I felt that the compelling part of this discussion was not the separate ways that the teachers found to describe potential energy, but how they tried to reconcile their own understandings with their peers, develop a coherence in their own understandings, and argue for their own stances. The teachers presented supportive and contradictory examples, they attempted to formulate hybrid descriptions, and they tried to determine predictions that could distinguish between the different descriptions.

Again, I didn't really have a research agenda when observing these teachers. While I had some relevant theoretical perspectives in various levels of digestion, I felt that full discusion among the I-RISE scholars would illucidate some other interesting perspectives. And although the discussion about cheating by attributing additional attributes to energy beyond conservation, transferability, and transformation occured during Hunter's subsequent presentation, I'm curious how that might apply to the idea that energy is stored in an object - that is, "storage" or "dormancy" is consitered to be an additional attribute of energy. Indeed, when coming up with a gesture for potential energy during an earlier Energy Theatre activity, the teachers immediately gestured as if they were sleeping (see my earlier blog post for that video.)