The Role and Potential Dangers of Visualisation when Learning about Sub-Microscopic Explanations in Chemistry Education

Ingo Eilks,Torsten Witteck,Verena Pietzner

doi:10.26529/cepsj.398

Abstract

The core of theory-driven chemistry education consists of the constant shift between the different representational domains of chemical thinking: the macroscopic, the sub-microscopic, and the symbolic domains. Because the sub-microscopic domain can neither be seen nor directly visualised, it requires specific forms of visualisation, i.e. pictures andanimations illustrating the model-based level of discrete particles, atoms, or molecular structures. This paper considers the central role visualisations play when learning about the model-based, sub-microscopic level, but it also reflects the dangers inherent in employing insufficiently examined, poorly considered, or even misleading visualisations. This is outlined using different examples taken from both textbooks for lower secondary chemistry education (for students aged 10 to 15) and from the internet. Implications for structuring and using sub-micro visualisations in chemistry education are also given.

Highlights

The core of theory-driven chemistry education consists of the constant shift between the different representational domains of chemical thinking: the macroscopic, the sub-microscopic, and the symbolic domains
Understanding the learning of science is today regularly referred to the theory of ‘constructivism’ (Bodner, 1986)
The given particle model-based visualisation used in this textbook suggests this interpretation has been scientifically proven and accepted by all teachers of science, giving it credence in the learner’s eyes

Summary

The essential role of visualisation for teaching and learning chemistry

Understanding the learning of science is today regularly referred to the theory of ‘constructivism’ (Bodner, 1986). Studies have been performed that investigate students’ alternative conceptions, how they are related to understanding the states of matter, which changes take place between them, and what types of sub-microscopic, model-based explanations are given for them The given particle model-based visualisation used in this textbook suggests this interpretation has been scientifically proven and accepted by all teachers of science, giving it credence in the learner’s eyes Such an interpretation is a complete contradiction of the macroscopic behaviour of matter. Students sometimes have the idea that new substances or particles are formed during evaporation, ones which had not been part of the initial liquid (Osborne et al, 1983) This scientifically incorrect concept is portrayed in the right animation (lower picture): the water molecules are generated inside the bubbles within the boiling water. Many other examples exist that deal with commonly known alternative conceptions among learners for both this topic and for many other topics in the internet, e.g. Eilks et al (2009, 2010) gave a detailed discussion of the mismatch still occurring between current research evidence and classroom materials prepared for visualisation of the Daniell voltaic cell

Explaining the liquid and gaseous states of water

Biographical note