WHY STUDENTS HAVE DIFFICULTIES LEARNING ABOUT ROCKS AND THEIR FORMATION

Although rocks are one of the fundamental topics in geology, little research has investigated college students' conceptions of them. In order to learn their conceptions of rocks, we researched the ideas of 208 college students after they learned about rocks in 13 different introductory geology classes, using a questionnaire and interviews. Overall, our research shows that most students view rocks as objects and do not link them to the processes that form and change them. This view may be caused by conceptual barriers (described below) blocking learning of rock formation as well as the lack of intuitiveness of the three rock types established by geologists. Many students have a basic knowledge of rocks, but the knowledge is not structured in such a way that there are connections between the concepts of rocks and their formation. Because students do not have a holistic understanding of rocks, this perspective of rocks solely as objects obstructs learning, since they cannot truly learn the importance of rocks to geology.

In addition, we identified many of the alternative conceptions students have about rock formation. We then used themes within those alternative conceptions to identify the underlying conceptual barriers that cause them. Conceptual barriers are deeply-held conceptions that prevent students from understanding scientific explanations. The seven conceptual barriers identified in this study that prevent students from understanding rock formation are Deep Time, Atomic Scale, Large Spatial Scale, Changing Earth, Bedrock, Materials, and Pressure. Because of these conceptual barriers, students cannot form scientifically correct mental models of how rocks form, resulting in alternative conceptions, so the conceptual barriers need to be overcome before students truly learn the scientific explanations of how rocks form. The results of this study can be applied to other areas of geology in addition to rock formation.