Supporting Student Conceptual Model Development of Complex Earth Systems Through the Use of Multiple Representations and Inquiry

Journal of Geoscience Education, May 2006 by Sell, Karen S, Herbert, Bruce E, Stuessy, Carol L, Schielack, Janie

ABSTRACT

Students organize scientific knowledge and reason about issues in the Earth sciences by manipulating internally-constructed mental models and socially-constructed, expressed, conceptual models. The Earth sciences, which focus on the study of complex, dynamic, Earth systems, may present unique cognitive difficulties to students in their development of authentic, accurate expressed conceptual models of these systems. This pilot study came about as we were seeking to construct inquiry modules to assist undergraduate students as they developed an understanding of eutrophication along the coastal margin, a good example of a complex, dynamic, environmental process. The modules we developed coupled the use of physical models and information technology (IT)-based multiple representations with an inquiry-based learning environment that allowed our students to develop and test their conceptual models based on available evidence and to solve authentic, complex, and ill-constrained problems. Our hypothesis was that the quality of students' conceptual models would predict their performance on inquiry modules, and that students' prior knowledge (measured by number of previous courses in geology) would mediate the strength of the relationship between students' model expression and their inquiry performance. Statistical results of this study indicated such a relationship existed only among students in the high prior knowledge group. In the light of our findings, we make recommendations for pedagogical accommodations to improve all undergraduates' abilities to understand complex, dynamic, environmental systems, with a particular emphasis on students who have lower levels of prior knowledge.

INTRODUCTION

Student Conceptual Model Development - Cognitive scientists and science education researchers have used the term mental model to describe internal representations of external, natural phenomena (Centner and Stevens, 1983; Johnson-Laird, 1983; Johnson-Laird and Byrne, 1991; diSessa, 1993; Doyle and Ford, 1998). A mental model becomes expressed once it is represented or communicated through drawings, symbols, objects or words. Recently in Earth science education, the term conceptual model has been used to describe students' expressed mental models, defined as an accurate, reasonable representation of natural phenomena that is adopted by groups and indicates a level of expertise (Greca and Moreira, 2000; Libarkin et al., 2003). Scientific models, a type of conceptual model, are used by scientists as cognitive tools to aid in experimental design, develop understanding of complex systems through comparisons with observations, and to make qualitative and quantitative predictions concerning system behaviors under specified conditions. Engagement in authentic practices, which are similar to the activities and tasks performed by scientists, is recommend as a way to support conceptual change among students (Carey, 1985; Vosniadou and Brewer, 1987; She, 2004).

Understanding and manipulating conceptual models of complex Earth systems can present significant learning difficulties for many students (Herbert, 2005).

Common learning issues include limited meaningful conceptual understanding of associated knowledge domains and the use or na�ve models that guide explanations (Sanger and Greenbowe, 1997; Harrison and Treagust, 1998; Coll and Treagust, 2003; Guisasola et al., 2004). Specific learning issues surrounding student understanding of complex Earth systems include student conceptualization of dynamic Earth systems in static disjointed terms and identification of a single causal factor to explain complex natural phenomena (Raia, 2005).

The Role of Prior Knowledge in the Development of Conceptual Models - It is well established that prior knowledge influences learning (Mintzes and Wandersee, 1998; She, 2004). A common view of learning is that students construct new knowledge and understandings based on what they already know (Bransford et al., 1999); this view is often considered a constructivist view. It is based on the premise that the learner selects and transforms information from past and current knowledge into new constructs and decisions. Since students come to courses in the Earth sciences with a range of prior knowledge, skills, beliefs, and misconceptions, their abilities to remember, reason, solve problems, and acquire new information is affected (Bransford et al, 1999). If the instructor pays attention to the prior knowledge of their students, it has been evidenced that learning is enhanced (Bransford et al, 1999). Although there may be a number of other variables that may affect student learning of complex Earth systems (e.g. student science attitudes/ motivations, instructor pedagogical content knowledge, gender differences, and student visualization/spatial ability), we felt that student prior knowledge was the most important variable to base our study because of the range of knowledge backgrounds that frequently characterize students enrolled in Earth science courses.