Seventh grade students' mental models of the greenhouse effect

Abstract

This constructivist study investigates 225 student drawings and explanations from three different schools in the midwest in the US, to identify seventh grade students' mental models of the greenhouse effect. Five distinct mental models were derived from an inductive analysis of the content of the students' drawings and explanations: Model 1, a ‘greenhouse’ for growing plants; Model 2, greenhouse gases cause ozone depletion or formation, causing the Earth to warm; Model 3, greenhouse gases, but no heating mechanism, simply gases in the atmosphere; Model 4, greenhouse gases ‘trap’ the sun's rays, heating the Earth; and Model 5, the sun's rays are ‘bounced’ or reflected back and forth between the Earth's surface and greenhouse gases, heating the Earth. Science textbooks are critiqued in light of the students' mental models and curricular and instructional implications are explored.

Keywords:

• climate change
• conceptions
• constructivism

Notes

1. The studies are from the 1990s onwards, and largely with students in western, industrialized states, e.g., European countries, Canada, Australia, etc.

2. The work reported in this manuscript was supported by the National Science Foundation (NSF), award number Geo 0606922. It is also described in Shephardson et al. (2009).

3. The coding represents (school–grade–student number), as used in Shephardson et al. (2009).