Finding faults: analogical comparison supports spatial concept learning in geoscience

Abstract

A central issue in education is how to support the spatial thinking involved in learning science, technology, engineering, and mathematics (STEM). We investigated whether and how the cognitive process of analogical comparison supports learning of a basic spatial concept in geoscience, fault. Because of the high variability in the appearance of faults, it may be difficult for students to learn the category-relevant spatial structure. There is abundant evidence that comparing analogous examples can help students gain insight into important category-defining features (Gentner in Cogn Sci 34(5):752–775, 2010). Further, comparing high-similarity pairs can be especially effective at revealing key differences (Sagi et al. 2012). Across three experiments, we tested whether comparison of visually similar contrasting examples would help students learn the fault concept. Our main findings were that participants performed better at identifying faults when they (1) compared contrasting (fault/no fault) cases versus viewing each case separately (Experiment 1), (2) compared similar as opposed to dissimilar contrasting cases early in learning (Experiment 2), and (3) viewed a contrasting pair of schematic block diagrams as opposed to a single block diagram of a fault as part of an instructional text (Experiment 3). These results suggest that comparison of visually similar contrasting cases helped distinguish category-relevant from category-irrelevant features for participants. When such comparisons occurred early in learning, participants were more likely to form an accurate conceptual representation. Thus, analogical comparison of images may provide one powerful way to enhance spatial learning in geoscience and other STEM disciplines.

Appendix: Instructional text from Experiment 1

To make a mountain, Earth forces lift cubic kilometers of rock skyward against the pull of gravity. The process of mountain forming not only uplifts the surface of the crust, but also causes rocks to undergo deformation, a process by which rocks squash, stretch, bend, or break in response to squeezing, stretching, or shearing. Geologists refer to the changes in shape caused by deformation as strain. Sometimes the rock changes only temporarily and then changes back when the force that caused the strain is removed—an elastic strain. Rocks can also develop permanent strain, in two fundamentally different ways. In ductile deformation, a material changes shape without breaking, like a ball of dough squeezed beneath a book. However, during brittle deformation, a material breaks into two or more pieces, like a plate shattering on the floor.

A fault is an example of a brittle deformation. A fault is a fracture in Earth’s crust along which there has been slipping (or displacement) of the rocks. The amount of displacement can vary from a fraction of an inch to many thousands of feet. Some faults, like the San Andreas, intersect the ground surface and thus displace the ground when they move. Others involve the sliding of rock at depth within the crust and remain invisible at the surface unless later exposed by erosion. Movement along a fault generally takes place suddenly, commonly involving distances up to 20–40 feet, and rarely more.

You can see that a fault is a fracture in Earth’s crust along which there has been slipping (or displacement) by examining the fault block diagram below. The diagram displays a fracture, and there has clearly been movement along it. In order to identify a fault, you must find evidence that the rocks on either side of an apparent fracture have been displaced. Note that this movement can be in any direction along the fracture, that the amount of movement can vary in different faults, and that the angle of the fault may also vary.

In this task, you will be presented with photographs of geological structures. Some of the photographs will contain a fault. Your job is to determine which photographs display a fault.