Exploring undergraduates’ conceptions of elasticity, within a plate tectonics context, before and after experience with rock’s elastic behavior

Abstract

The elastic rebound theory is a fundamental explanatory geoscience construct introduced in most introductory undergraduate geoscience courses. Classroom experience, supported by a recent case study of undergraduate students’ model-building activities, indicates that learning this theory tends to be incomplete, in spite of instruction employing external representations and other analogies. Using conceptual metaphor theory as a lens to investigate such instruction, this project sought to document students’ understandings of elasticity within a plate tectonics context, and identify and describe learning demands that must first be addressed for analogies and models to be effective. The project also evaluated the efficacy of an instructional intervention that provides learners with an experience with rocks that most daily encounters do not: the elastic deformation of rocks. Using a nonequivalent groups design of 81 undergraduate students enrolled in a 100-level geoscience course, this work revealed that prior to instruction all participants were familiar with the concept of elasticity. However, only 35.8% were able to demonstrate an understanding aligned with the scientific consensus. Relevant to the elastic rebound theory, just over 50% conceptualized tectonic plates and Earth’s upper interior as being composed of rocks, and 67.9% identified tectonic plates as elastic. However, indicative of a shallow understanding, only 18.5% recognized that rocks, which make up tectonic plates, behave elastically. The instructional intervention that allowed students to bend rocks resulted in a statistically significant increase in the number of students who conceptualized rocks as well as other solids as elastic on the posttest.