The Impact of Secondary School Students' Preconceptions on the Evolution of their Mental Models of the Greenhouse effect and Global Warming

Abstract

This paper provides a video-based learning process study that investigates the kinds of mental models of the atmospheric greenhouse effect 13-year-old learners have and how these mental models change with a learning environment, which is optimised in regard to instructional psychology. The objective of this explorative study was to observe and analyse the learners' learning pathways according to their previous knowledge in detail and to understand the mental model formation processes associated with them more precisely. For the analysis of the learning pathways, drawings, texts, video and interview transcripts from 12 students were studied using qualitative methods. The learning pathways pursued by the learners significantly depend on their domain-specific previous knowledge. The learners' preconceptions could be typified based on specific characteristics, whereby three preconception types could be formed. The ‘isolated pieces of knowledge’ type of learners, who have very little or no previous knowledge about the greenhouse effect, build new mental models that are close to the target model. ‘Reduced heat output’ type of learners, who have previous knowledge that indicates compliances with central ideas of the normative model, reconstruct their knowledge by reorganising and interpreting their existing knowledge structures. ‘Increasing heat input’ type of learners, whose previous knowledge consists of subjective worldly knowledge, which has a greater personal explanatory value than the information from the learning environment, have more difficulties changing their mental models. They have to fundamentally reconstruct their mental models.

Keywords:

• Greenhouse effect
• Preconception types
• Conceptual development
• Learning process analysis
• Mental model evolution

Acknowledgements

The authors thank Dr. Urs Aeschbacher for his significant contributions to the success of this research. Our thanks also go to the teacher Anita von Däniken and her students who participated in this study. We would also like to thank the reviewers for their thoughtful comments on an earlier draft of this paper. This research was funded by the Foundation of the University of Teacher Education Central Switzerland, Lucerne.

Notes

1. In Switzerland, a grading scale of 1–6 is used, in which 6 is the best grade.

2. Hans Aebli, a well-known psychologist and educator in Switzerland, was a student of Piaget and further developed Piaget's cognitive-constructivist theory, to make it applicable in a didactic manner.

3. We slightly altered the diagram in the first image−text unit of the worksheet compared to the one used in GeoConcepts I (cf. Reinfried et al., 2012). Instead of graphically portraying a hole in the atmosphere, we only addressed it in the form of a question. This was necessary because several students did not immediately recognise the hole in the worksheet for GeoConcepts I as an illustration of a widespread misconception. In GeoConcepts I we used the hole conception as a starting point in the worksheet, assuming that in doing so, we are addressing the initial mental models of many learners.

4. The MED (www.demoex.ch) is set up as follows: A rotating desktop globe, heated by lighting, serves as an infrared radiation source. The Earth's atmosphere is shown as a section in the form of a plexiglass cuvette, which is open on top. The CO₂ is poured into the previously air-filled cuvette from the top on the unlit side—the night side. A measuring device, positioned outside of this ‘piece of atmosphere’, measures the intensity of infrared radiation, which enters into space from the heated surface of the globe through the ‘piece of atmosphere’. The measuring device immediately indicates a decrease in this intensity, when the CO₂ is poured in. Therefore, it is not a matter of a precise measurement but rather of the qualitative immediate effect of the falling needle. A video demonstration of the MED is available in German on www.demoex.ch/?Produkte → Schülervideo.

5. The content validity of the categories resulted from the analysis of specialist literature (IPCC, 2007; Schönwiese, 2003; Weischet & Endlicher, 2008), from the analysis of several studies which discuss cognitive constructs based on misconceptions (Aeschbacher et al., 2001; Andersson & Wallin, 2000; Bord, O'Connor, & Fisher, 2000; Boyes & Stanisstreet, 1993; Dieckmann & Meyer, 2007; Dove, 1996; Kempton, 1993; Koulaidis & Christidou, 1999; Löfstedt, 1992; Read, Bostrum, Morgan, Fischhoff, & Smuts, 1994; Rye et al., 1997; Schuler, 2011), from the analysis of 61 teaching materials (textbooks and instructional texts) and 37 web pages in which the misconceptions were also found (as at May 2009), from the discussions of the categories with three experts (a climatologist, a physicist and a psychologist) and from the previous success with the categories in the quantification of the knowledge gain of the learners in GeoConcepts I (cf. Reinfried et al., 2008, 2012).

6. Omissions in the following transcript excerpts are marked with … The language in the transcripts is slightly improved. The information in square brackets designates comments added by the authors.