Last night Rosalie facilitated a lecture-discussion on heat, developing students’ ideas about energy transfer and how to do problems. I noticed a couple of times students gave the "right" answer, but when Rosalie probed further, the students didn’t really understand what they were talking about. It would have been easy to accept the correct answer as proof of understanding and then move on. The extent of students’ not knowing was profound, and it took some time to uncover its true dimensions.
I’m reminded of diSessa’s construct of p-prims, which he describes (to the best of my recollection) as conclusions about phenomena which are not linked to other ideas, but remain as islands. When Rosalie asked students to make connections or to create a chain of causal reasoning, they were able to do so only with great difficulty and a great deal of prompting in the form of questions. She engaged individual students in extended questioning in order to scaffold putting together a cohesive whole.
I noticed that not all students were following the conversation and did not seem to understand that their colleagues’ were being questioned publicly in this way in order to get ideas onto the table for everyone to consider. Earlier in the evening students repeatedly focused on the right answer, and when someone came up with an answer that was judged to be correct, it was quickly passed around. At the time Rosalie announced that we were not really interested in the correct answer, which the students seemed to shrug off. I think that they don’t have any other perspective on science calculations, and the idea of viewing problems as a shorthand for science concepts is an entirely new idea for them.
At the end of Rosalie’s discussion of heat, I felt that we should call students’ attention to what we had been doing by investigating their ideas in depth. I had two purposes in doing this. One was to let students know that the structure of our lesson was deliberate, and that we had a particular pedagogical goal in mind. I also wanted to clue in those students who had not been paying attention that perhaps this was important. I reiterated that we were not interested in formulas, but that they should focus on understanding the problem; understanding makes the strategies for solving it obvious. Rosalie reiterated that she too is not interested in students memorizing formulas. I also explained that there had been several times during the lecture when students had appeared to give the correct answer, but Dr. Richards kept probing, and it was revealed that the students did not really understand. I tied this to the issue of deciding what to accept as evidence of learning, and asked whether they had run into this phenomenon in their field placements.
I will say that we started the evening with a wide ranging discussion of the role of energy in the body, and the way chemical energy of food is transferred through digestion and metabolism. I was expecting students would not relate the process of combustion from the lab of calories obtained by burning Cheetos with the breaking of chemical bonds within food substances. I discovered this some years ago in teaching high schoolers, when I would ask them why they need oxygen, and the students were unable to go beyond because you can’t breathe and you’ll die. What a shame it is that we don’t explore the big picture and assume that students have made connections such as the role of oxygen in both combustion and cellular respiration.
The conversation about heat contained within food revealed that students remember very little of any high school biology.
The previous night in one of my graduate classes we started exploring the idea of their perceived lack of connection between learning and completing assignments. Before Rosalie came in, I decided to see what the undergrads had to say about this topic. They basically said they had to choose: either do the assignment and get the points, or study and try to understand. I wondered whether the purpose of doing assignments is to facilitate learning.
We did not get very "far" in our discussion of heat, although we perhaps got deep. I came away from last night’s class with another piece of evidence I interpret as showing the need to explore ideas in depth, and the conviction that most science instruction merely papers over students’ confusion.