Implications for Field Geology Instruction from a Behavioral Study on How Students Gather, Represent, and Integrate Spatial Information about Dipping Surfaces

We are researching how geologists and students gather, represent, and integrate spatial information about the attitude and location of dipping layers, a skill set underlying success in field geology.

In the constituent-skills component of the study, undergraduates observe an artificial "outcrop" installed on the Penn State campus, a tabletop model of a dipping surface, and/or a rod lying on the table or ground. Tasks include sketching strike or rod orientation onto a map, estimating dip angle, and drawing strike line or "water level" directly onto the dipping surface of the tabletop model. We examine performance in relation to the nature of instruction, the strike and dip of the tabletop model, the orientation of the rod, and the gender and spatial skills of the participants.

In the integrative component of the study, participants observe an array of eight artificial outcrops, which have been installed on the L-DEO campus so as to form a "structure" at a realistic scale. After observing and taking notes on the outcrops, participants choose from among fourteen 3-D scale models the one that they think best represents a structure that could be formed by the outcrops. Participants are videotaped while selecting and explaining their model.

Implications for field geology instruction: Dip is an easier and more obvious concept for students than strike, and might be better taught first. Students' spatial skills are associated not only with their performance on strike and dip tasks, but also with the likelihood that they will spontaneously adopt useful (and teachable) spatial strategies such as scanning middle-distance landmarks in the surrounding environment. Almost everyone overestimates dip angle, across a wide range of circumstances. Physical models can scaffold students' perception (e.g., in "seeing" the strike line in a dipping surface) and students' reasoning (e.g., in identifying attributes of outcrops to incorporate in interpretation).