STUDENTS' ANALOGIES AS INSTRUCTIONAL AND ASSESSMENT TOOLS IN EARTH SYSTEMS SCIENCE

This study tests the hypothesis that college students can draw inferences about earth systems through understanding and creating analogies. Most commonly people learn through drawing inferences from simple causal analogies. This common practice provides a mechanism for assessing learning when the goal of learning is the ability to draw inferences. Analogies are important for assessing learning about earth systems, in particular, because most inferences that novices can draw about global change are based on analogy (e.g., a bathtub analog for reservoirs and fluxes). Our subjects were 160 non-science majors at a large state university in the Midwestern US. During the semester, students were given explicit instruction and many opportunities to practice using analogies to generate inferences. Analogies were scored based on three components: 1) description of correct similarities between analog and target, 2) causal similarity, and 3) correct inference. Correct identification of similarities, only indicates lower level understanding, defined as knowledge and comprehension in Bloom’s taxonomy. Recognition of causal similarity and ability to draw inference indicate higher-level understanding that requires analysis and evaluation.

Students drew analogies to processes in the rock, water and carbon cycles. Initial results show that approximately 85% of students described correct similarities between analog and target, 25% stated causal similarities, and 15% drew correct inferences. Related assessment of students’ understanding of earth systems using box and arrow diagrams confirms that approximately 80% of students are proficient at the level of knowledge and understanding. Our results point to a very large gap between students’ understanding and their ability to draw inferences about earth systems. This work raises questions about students’ ability to reason about earth systems.