HELPING TO IMPROVE NON-SCIENCE STUDENTS’ CONCEPTUAL UNDERSTANDING OF THE GREENHOUSE EFFECT

Student misconceptions about complex Earth processes are common, in particular the greenhouse effect. Students often misunderstand the processes involved and therefore misrepresent the phenomena in drawings. For example, drawings may include the Sun but lack a connection between the greenhouse effect and the Sun; may include a physical greenhouse; or may include holes in the atmosphere. This study tracked 48 non-science elementary education students through pre-, post-, and end of semester conceptual drawings of the greenhouse effect to examine longer-term retained conceptual understanding. Using a model analysis developed in an earlier study, we looked for common features in the drawings, as well as integration between features. Analyzed features were based on common student ideas and included the Sun, incoming energy, a gas layer, and ozone. We also looked for processes such as energy change and or absorption at the Earth’s surface, the distribution of gases throughout the atmosphere, and energy being re-emitted by greenhouse gases. Pre-tests of these non-science elementary education students showed that less than half of them understood that the greenhouse effect did not involve an actual greenhouse. In order to help support sustained conceptual understanding of climate change, the course instructor explicitly broke down student misconceptions and addressed them one-by-one with the class multiple times. This included working in groups and as individuals to incorporate new knowledge through the use of student drawings, professional drawings and animations, in-depth discussions, peer-teaching, and peer-evaluations. Post-tests showed considerable improvement among their conceptual understanding, with inclusion of accurate features to express the greenhouse effect as well as interactions among these features. An additional post-test was included at the end of the semester, eight weeks later, to examine students’ longer-term retention, and indicates significant retention. Taken together, these data suggest that addressing student alternative conceptions is a useful approach to sustained student understanding.