Student Difficulties with Groundwater and Oil Storage: Do Textbook Visualizations Support (Mis)Conceptions?

As part of a larger effort to measure student conceptual learning in introductory physical geology courses, we are investigating how students visualize groundwater and oil storage through open-ended and multiple choice survey questions, student interviews, and classroom observations. Prior to course instruction, approximately the same percent of students (35-45%) visualized most groundwater and oil occupying caverns or lakes underground (in otherwise empty space) as saw groundwater and oil as primarily occupying pore space. Across different teaching and learning environments (i.e., lecture-centered with multiple choice exams to moderately interactive courses with homework and in-class activities), and a sample of >500 students, most students (55-90%) completed the course thinking that groundwater is primarily found in pore space. Our results suggest that this particular misconception regarding groundwater storage can be fairly easily corrected with current teaching approaches and textbook treatments. In contrast, most students left the course still believing that oil was found in caverns or lakes. Students also displayed other misconceptions previously documented for elementary school students, such as misunderstandings concerning oil formation. In interviews, some students pointed to textbook diagrams as a source of confusion, in which groundwater is shown residing in pore spaces of a sandstone-like “matrix”, whereas no matrix is shown for diagrams with oil. A survey of four commonly used introductory physical geology and two environmental geology textbooks found that all books show a sandstone-like matrix in some or all visualizations of groundwater. Only two introductory physical geology books have any visualization of oil showing matrix. We suggest that textbook visualizations can reinforce both “expert” and “novice” conceptions, and that typical visualizations of oil storage are misleading.