Sunday, March 05, 2006

Sporadic Turns To Hiatus

My already sporadic posts are about to be even more so as I wind down the school year and get more and more swamped with my masters project. This will be the last post for some time.


My students are working on their carbon autobiographies, with varying degrees of success. Some are really taking off with it, delving into the details of all the processes that happen as a carbon atom cycles through the environment. Others are dragging their feet or doing a strictly mechanical job of complying with the minimal requirements of the assignment with little enthusiasm. I totally understand, on the one hand, and would myself probably be the kind of student who couldn't get into this project much. On the other hand, it REALLY highlights just how fragmented their knowledge is - they really struggle to put the pieces together into a coherent narrative and I think that makes it a valuable exercise. Below I outline some of the problems with this assignment, but the students' problems start way before these issues even come up - for example, they totally gloss over the photosynthesis and respiration parts, which they are expected to know at this point.


Here's a basic description of the project, Carbon Project, which I keep revising as I run into complications. Some of the processes are rather complex and I will make revisions again for next year. For example, cellulose synthesis is not completely understood and the only literature I can find on the web is highly technical and beyond a high school student's comprehension, so I've had to summarize some of it for them. Similarly, the digestion of cellulose in cows is a complex process. I originally used pigs, but that's even more difficult to figure out. I have taken the more complex parts and simplified or summarized for student in class, they just have to weave the science into their stories and find appropriate images to accompany the stories.


Elsewhere, my masters project is about teaching/learning evolution. Here's my basic premise. The conceptual change model, which I think is a useful one, suggests that students come to us with existing conceptions about how the world works. A typical example is the "naive" conception that summers are warmer than winters because the sun is closer to the earth in summer and farther away in winter. If we ignore this naive conception, we will get the student in class to parrot what we say about the tilt of the earth and all that, but in a short time or with a little pushing, we will find that they really still hold on to their original beliefs. Conceptual change models suggest addressing student pre-existing ideas up front, setting up inquiry activities that produce cognitive dissonance (where the naive conception breaks down), then offering an alternative (scientific) schema that explains the phenomenon better. That's it in a nutshell.


So how do we apply this model to the teaching of evolution? Inevitably this approach will lead to bringing religious discussions into the classroom since many students prior conceptions about origins of species (especially human) will come from religious stories. My preliminary research suggests that most teachers are not comfortable approaching evolution in this way, but the consequence may be that we are "covering" evolution in class but our students are coming away with not much understanding to show for it. My plan is to in fact have this discussion with students, offering them a range of options for how do deal with any conflicts between their personal (religious) beliefs and evolution, and investigate how their understanding of evolution is affected by this approach. I actually began thinking about this last year, and I posted a few comments about it here. I've got lots of details to work out so I should stop procrastinating NOW and get on it.