I'm still getting used to teaching Biology to 9th graders (as opposed to 10th graders) who haven't yet been exposed to the CER framework or any modeling exercises. For a warm up this week, I asked the students to draw a model (explanation) of what happened in their greenhouse investigations from before break. It was a train wreck. However, it did give me insight into (a) their lack of understanding of what a model is and (b) their shaky conception of the greenhouse effect and its relation to the carbon cycle. What to do? Scaffold, scaffold, scaffold.
So I put everything else on hold for a day and a half, and the students practiced designing models, with help from me along the way. I started with direct instruction and gradually released the task to them. They probably created close to ten models in the course of 2 class periods. Afterwards, I assessed them again with a warm up: "Diagram a model of how rice cooks." (I wanted something that all students were familiar with and wasn't overly complicated. The results were amazing. One student drew the steps for how rice cooks instead of an explanation, but was able to make corrections once prompted. Otherwise everyone was on target. Whew.
|Practice models for the Greenhouse Investigation. Getting better!|
By the way, I designed this CER on a real-life data set of lab mice at the University of California, Riverside. The mice were artificially bred to run for long periods of time. I got the idea from this site, http://www.indiana.edu/~ensiweb/lessons/BornToRun.html, and reworked it a little to make it more CER-friendly. The students developed their own research questions and method of measurement. They were able to incorporate standard deviation and standard error of the mean into their calculations. It ended up being a very robust investigation.
In Environmental Science, students are working through a unit I decided to call "Principles of Ecology." I had them complete a pre-assessment to see what types of Ecology topics they remembered from Biology, and then designed the unit around what they had forgotten. I've wanted to have students build Winogradsky columns for many years, but it never fit perfectly into any of the standards. However, range of tolerance is one of the Ecology topics my ES students are learning about, and the columns fit in perfectly! It was a challenge to find mud from a stream or pond in metropolitan Seoul, but I successfully trekked down to the local canal before school one day and dug up a bunch of sediment. With no buckets or trowels to be had, I used a plastic storage crate my sons keep LEGO in and a soup ladle. I got some strange looks from the elderly Koreans and commuters on the bike/walking trail. The sediment was pretty sandy, so I'm hoping it works okay. The ES students had fun mixing in the newspaper and egg yolk for carbon and sulfur resources. One student had never separated a yolk from the egg white before, so he even learned a new baking skill - bonus!
To model limiting factors, ES students did some "hunting" of yellow, puffball mice with pipe cleaner owls. Kind of reminded me of the "ring the bottle" game I used to see at county fairs. The class will be writing CER arguments based on their results in class next week.
One final accomplishment for the week: I found a bike and rode it to work a couple of times (not on the day when I had to collect canal sediment, though!). It feels good to be getting into a rhythm and feeling comfortable in my new city and new school.