PLATE TECTONICS AS VIEWED BY NOVICES AND EXPERTS

The Theory of Plate Tectonics is fundamental to how geologists interpret many geological processes. As such, one might expect that as students progress from undergraduates to professional geologists, they will develop an accurate understanding of plate tectonic concepts. As part of a study investigating this claim, sixty one-on-one interviews were conducted with participants ranging from non-science major college students enrolled in a general-education science course to expert geoscientists whose research is directly related to plate tectonic processes. Interviews utilized a modified version of a schematic cross-section that illustrates various plate tectonic processes. The original schematic is supported by national geological organizations and widely reproduced in textbooks and online. As would be expected, the total number of correct concepts increases, and the number of alternative conceptions decreases, as one moves from being a novice towards becoming an expert. At the same time, as people gain proficiency in plate tectonic concepts, they are likely to acquire new alternative conceptions related to aspects of the plate tectonic model that are beyond the scope of a novice’s viewpoint. A common novice-level alternative conception is the interpretation of a divergent zone as a convergent boundary, often because the novice sees the plates as pushing each other up. Alternative conceptions that are present deep into the expert-novice continuum include: the mantle consists of a significant fraction of magma; dewatering of pore spaces during subduction is the cause of hydration melting in subduction zones; and, transform faults initially offset spreading axes prior to reactivating in the opposite direction to accommodate spreading. Research findings indicate that most geoscientists who are not actively involved in a field directly related to plate tectonics, whether students, professional geoscientists, or geoscience faculty, likely hold a few alternative conceptions related to, or are simply unaware of, fundamental aspects of the plate tectonic model. This leads to the question: If only the most expert hold complete models of fundamental phenomena in one domain, then how can the general public be expected to comprehend accurate models across a wide range of scientific domains?