Selecting big ideas/models
Last year Janet taught a unit on fungi but had the sense that the unit experiences were disconnected and that the students were not able to retain a lot of the information they learned. The focus was on fungi as a kingdom and the students learned about the phyla within the kingdom. They did a series of activities such as a mushroom walk around the school, making spore prints, and learning about the ecological role of fungi. They also did an experiment to create the “best recipe” for yeast metabolism. The students were actively involved in the experiment but their focus tended to be on how much carbon dioxide was produced by the yeast. Students read about the role of sugar in cellular respiration and chose to manipulate the carbohydrates and sugars they gave to the yeast but some students also chose to add items like lemon juice. Most students understood that a chemical reaction took place but some students did not attribute the reaction to a metabolic process in the yeast--visualizing instead something more like vinegar and baking soda as the reason for gas production.
This year Janet shifted the focus of the unit to the interrelationships of four fungi life processes. Fungi were used as examples to show how these life processes were characteristic of all living things. She chose to focus on the role of fungi in decomposing matter, how they digest matter, how they use cellular respiration to generate energy from sugars, and why they use this energy—which is chiefly for reproduction. In this way the unit shifted from being about yeast as a topic with some focus on processes to being about an explanation for why yeast decompose organic matter. Students worked with the following model:
To focus students on the idea that yeast exemplify processes of all living things and to generate student interest, Janet used the essential question “How am I similar/different than fungi?” to frame the unit.
Topic focus |
Process focus |
Theory focus |
Janet selected a theory-focused big idea for her unit of instruction. As such, the students worked toward understanding relationships among science concepts and toward connecting observable phenomena to unobservable explanations throughout the unit. In the graphic above you can see a 3-level continuum for how a teacher could focus a unit of instruction. A "topic focus" is the least effective way to frame a unit (leads to superficial forms of learning). The "process focus" is more effective and the "theory focus" is most effective.
