Post-secondary science students’ conceptions of randomness and entropy

Abstract

Thermodynamics and entropy are important aspects of secondary physical science. The molecular approach to thermodynamics provides insight into how the random motion of molecules results in regular properties of substances. The purpose of this research was to understand post-secondary science students’ conceptions of randomness and entropy and how they integrated these concepts.

The Probabilistic Thinking Framework of Jones, Langrall, Mooney and Thornton and the Attribution of Randomness Framework of Metz were used as a theoretical framework to construct how the participants used the concepts of probability and randomness in their discussion of entropy.

Case studies focused on eight post-secondary science students while enrolled in a science education methods course. Four semi-structured interviews and a questionnaire informed the case studies. Qualitative analyses of the data used the constant comparative method.

Three key findings resulted from the analysis of the data. First, a new method of measuring the complexity of two-dimensional grids was proposed. This new measure expands on the measure proposed by Klinger and Salingaros by including specific characteristics of the grids identified by the participants. Second, the participants exhibited subjective or transitional conceptions of probability and sample space. The findings demonstrated that they did not make any connections between probability and sample space with randomness. Third, the participants had an incomplete or instrumental knowledge of entropy. They did not make any connections between the underlying molecular properties and the measure of entropy.

Based on these findings, it has been suggested that secondary science teacher education programs include statistics and entropy in the science education curriculum or as part of a science education methods course. It is important for science teacher educators to emphasize the connection between molecular behavior and macroscopic properties. Finally, it is important for textbook publishers to consider carefully how textbooks represent molecular systems.