Ontology and the Teaching of Earth System Science

Journal of Geoscience Education, May 2006 by Libarkin, Julie C, Kurdziel, Josepha P

ABSTRACT

Student ontological level is an important consideration for faculty interested in teaching Earth System Science. Interviews with 61 students enrolled in entry-level geology courses at two institutions reveal that very few students exhibit Process or Systems ontologies. Earth Systems Science instruction generally assumes that students are thinking about processes and systems, although this study suggests that students predominantly understand that changes occur on Earth without either 1) a concrete acceptance that these changes result from a cause, or 2) an explanation for these causes beyond scientific terms such as "subduction". This has critical implications for teaching Earth System Science, and suggests that activities that can help college students develop Process and Systems ontologies need to be developed and evaluated.

INTRODUCTION

Earth System Science (ESS) education became popular in the U.S. after the publication of a NASA report promoting ESS as a tool for teaching undergraduates about complex earth interactions (NASA, 1988). ESS implies an integration of natural phenomena and society. The interplay between different Earth spheres, such as lithosphere, biosphere, and atmosphere, is viewed holistically, where changes or processes occurring in one domain will affect fundamental characteristics of all other domains. ESS at its most ideological will reproduce the world as one complex model, and at its most basic explains simple interactions between traditionally distinct natural or human domains. Regardless of the approach taken, teaching ESS requires first that students understand the importance of processes involved in the development of the Earth we experience today. Student ontological categories, then, are intimately tied to success in ESS courses.

The term "ontology" is used in a variety of contexts, and generally refers to the way in which people characterize phenomena. Chi and others (Chi et al., 1994; Chi, 1992) were the first to utilize the concept of ontology in an attempt to understand conceptual change within the domain of science. In this context, ontology refers to how someone perceives the nature of phenomena. Chi and others (Chi et al., 1994; Slotta et al., 1995) specifically divide phenomena into three categories: Matter, Processes, and Intangibles. They (Chi et al., 1994) argue that students generally categorize concepts into ontological categories, and that conceptual change is most significantly hindered when a shift from an alternative conception to a scientific conception requires a change in ontological category.

The reliance of ESS education on a basic understanding of processes implies that ontological categorization will fundamentally impact a students' ability to learn in an ESS classroom. Before we can determine how ontology affects the learning process, we must first characterize the ontologies held by typical undergraduates. We report here on an analysis of 61 interviews of undergraduate non-science majors enrolled in entry-level geology courses at two institutions. This analysis reveals the dominant ontological levels held by these students, with significant implication for development of effective ESS instruction.

BACKGROUND

The cognitive strategies used by novices and experts provide clues about origins of differences in problem-solving ability and mental models. In education, the comparison of expert-novice strategies suggests that experts are more flexible (Feltovich et al., 199/), are more aware of complexities in systems (Hmelo-Silver and Nagaraian, 2002), think more abstractly (Chi et al., 1981) or use abstract rules (Anderson and Leinhardt, 2002), and conceive of more complex connections between concepts (Hoz et al., 2001). Cross-age studies of grade 6 students through experts also indicate that organization of knowledge (Jong and Ferguson-Hessler, 1986), interpretation abilities (Means and Voss, 1985), and ability to think abstractly (Lewis and Linn, 1994; Wilson, 1998) increase with age. The appearance of alternative conceptions in novices has also been linked to novice problem-solving strategies (Heyworth, 1999).

The study of ontological categories (e.g., Chi et al., 1981) used by novices and experts in model development has provided significant insight into learning in several disciplines, including physics (Chi et al., 1981; Jong and Ferguson-Hessler, 1986), medicine (Hmelo-Silver and Nagarajan, 2002), and chemistry (Wilson, 1998). Some studies suggest that ontological levels change as students advance (e.g., Wilson, 1998), although ontological categorization in the geosciences is poorly understood. Libarkin and colleagues (2005) have extended the schema of Chi et al. (1994) to include Transformations and Proto-Processes based upon mental models of geologic time held by non-science majors enrolled in entry-level geology courses. Statements coded in the Transformation and Proto-Process categories would generally be placed in the Matter and Process categories of the original schema, respectively. The current study extends this work to ontologies utilized by entry-level students in thinking about all areas of physical geology.