Standard 7: Engagement with Subject Matter

Meeting Standard Seven:

"The student teacher demonstrates mastery of the skills and knowledge central to the discipline. Interest in, and energy for, his/her discipline are demonstrated through the creation of lessons which present diverse students with challenging activities and projects, engage them, and encourage them to solve problems, raise questions, and interact in ways that contribute to a positive learning environment while developing skills as critical, inquiring thinkers."

-Brown University Teacher Education Handbook

Overview

I always try to link subject matter to things that students have more familiarity with, such as by providing analogies or drawing connections to daily-life phenomena. For instance, I centered the first part of the ecology unit on a project that many students had familiarity with: keeping goldfish. Students generally loved the fishbowl activities and felt that they learned a lot by observing ecological concepts firsthand. Before diving into the details about blood in the cardiovascular system, I spent a class discussing the cultural and historical contexts of blood. This led to lively discussions about leeching and bloodletting, and more generally about how scientific knowledge changes over time and may be informed as much by cultural beliefs as by empirical evidence. I believe that making connections like these is important for helping students to engage with the subject matter and find personal meaning and relevance in them.

In the midst of trying to teach all the content required by the standards and the school curriculum, however, it can be easy to forget, at times, to teach science. The challenges brought on by the dense curriculum were compounded by the logistical difficulties of planning and running full-blown lab investigations when I had few materials available to me. Sometimes I stepped back and took a look at how many cold hard facts I was dishing out, and worried that my students might leave with the idea that science is all about memorizing vocabulary and intimidating concepts. To combat that, I periodically inserted "mini-labs" that required simple setups and procedures and inexpensive materials that I could buy myself. These mini-labs allowed students to explore concepts in a hands-on fashion and to practice formulating and evaluating hypotheses. For instance, we explored osmosis by placing gummy bears in different solutions and observing their change in size.

Sometimes labs have unintended results, which I made into teachable moments. For instance, we tried fermenting cabbage as an investigation about cellular respiration; however, as time went on, the pH of the cabbage went down and then up, and students became reluctant to handle the soggy and smelly mess. At this point, I could only salvage the lab by asking students what might have interfered with the fermentation process. Eventually we discovered a fungus growing on the cabbage, and students concluded that the cabbage may have become contaminated due to incorrect sealing of the bags.

Another teachable moment arose from an investigation on aerobic respiration. Students formulated hypotheses about the effects of exercise on the rate of color change in bromothymol blue, and designed their own procedure for testing their hypotheses. Most of the students did well with making sure to have a control and an experimental group. However, it was interesting to see how their expectations affected their observations and analyses. Some students hypothesized that exercise would increase carbon dioxide output and therefore speed up the color change in bromothymol blue, and that was the result that they observed. Other students, on the other hand, hypothesized that exercise would make one out of breath and less able to force a color change, and that was the result that they observed. Only one of these students discussed the idea that being short of breath might have been a confounding factor (not in those exact words). When I handed their write-ups back, I pointed out these discrepancies we had a discussion about the role of bias in scientific investigations.

Another way of exposing students to the scientific method is through presenting the work of scientists that led to the discovery of new ideas. This is a kind of storytelling, and it can take many different forms. I have done it informally (describing and modeling the experiments scientists did that led to the theory of photosynthesis) as well as making it a centerpiece of a lesson, as I did with Mendel’s experiments on pea plants. I introduced Mendel’s question and his experimental setups, and had the students follow along by describing Mendel’s procedure and making hypotheses about the results. This worked well, keeping students engaged, exposing their misconceptions and prior knowledge, and making them think about the scientific method employed by Mendel. In this way, even though we lacked the time or resources to make real-life genetic crosses in the lab, we are able to experience science at work through the interactive presentation of a story. Later, students put the principles into practice by tossing coins and drawing the faces of hypothetical children.