Research in Engineering Education Symposium 2011 - rees2009

Universidad Politécnica de Madrid (UPM) Página 705 de 957
teams (Gilbuena, Sherrett, & Koretsky, 2011). The pattern of discussion begins to
illuminate the interaction between student objectives and instructor objectives.
Throughout the coaching session we see smaller episodes relating to instructor objectives
nested within the context of larger episodes relating to student objectives. For example if
we look at the second row of discourse in Figure 1, discussions of diffusion and reaction
kinetics are nested within the larger context of pressure. The students must select a value
for pressure in order to proceed with their experiments; the discussion initiates
specifically addressing this need. The instructor then connects the core concepts of
diffusion and reaction kinetics as a way for the student team to think about their objective.
We next unpack this interaction.
The pressure episode begins after the temperature and sources episodes conclude; the
coach starts by directly asking the students how they determined the starting variable
value for pressure. They respond citing a literature reference, and state that they didn’t
think the pressure was as important as the other variables. The transition from strictly
focusing on the input parameter of pressure, a student objective, to diffusion as a focus is
illustrated in the following excerpt. It occurs with a question posed by the coach regarding
what affects pressure and the team's answer of 'diffusion:'
Coach: So what do you think affects pressure?
Student: Diffusion
Coach: So pressure is diffusion. In terms of diffusion where do you want the pressure
to be?
They discuss the core concept of diffusion, an instructor objective, for 275 words within
the context of its impact on the student objective, pressure. With probing, it appears the
team has a misunderstanding about the role of diffusion and the impact of pressure on the
performance metrics. The team is guided to conclude that diffusion is not the only way
pressure affects their performance objectives. A discussion of the concept of reaction
kinetics, another instructor objective, follows. The students are guided to relate pressure
to concentration and recognize its impact on reaction kinetics. The transcript excerpt
below shows the transition beginning with revisiting a previous question; the coach asks
what other thoughts the students have about why the pressure should not be set too low.
Students respond relating pressure loosely to reaction rate, after which the coach guides
the students with a leading question that focuses discussion on the contribution of
pressure to reaction rates.
Coach: Any other thoughts?
S1: That makes it, basically you are limiting, the thing that’s limiting what’s
happening would be how they hit and so you’d have to model basically the reaction
rate based on how they hit instead of
Coach: You talked about reaction rates, what are reaction rates a function…
S1: Temperature
Proceedings of Research in Engineering Education Symposium 2011
Madrid, 4 th - 7 th October 2011