BRIDGING THE GAP BETWEEN TABLETOP MODELS AND THE EARTH SYSTEM: CLASSROOM-BASED RESEARCH ON HOW TEACHERS TEACH AND STUDENTS LEARN FROM PHYSICAL MODELS

A fundamental problem in Earth Science education is that the Earth is roughly sixteen orders of magnitude larger than the classroom, and generally not available for experimentation. As a consequence, many hands-on activities use physical analogs for the phenomena that the curriculum is trying to elucidate, rather than the actual phenomena. To bridge from the tabletop model to the full-scale Earth System, students must transfer insights from small to large, concrete to abstract, visible to invisible, from manipulatible to out of human control. This is a difficult stretch, and is not well scaffolded by most existing instructional materials.

To better understand how teachers teach and students learn with physical models, we have begun a program of classroom-based research in four 8^th and 9^th grade New York Regents Earth Science classes. Research methods include teacher and student interviews, classroom observations with videotaping, and project-developed pre- and post-assessments of content and model-based reasoning. Data gathering is concentrated around three topics: deposition, lunar phases, and causes of the seasons.

Based on teacher interviews, choice of when to use a physical model is influenced by availability of the model and related curriculum materials, cost and logistics of using the model, and the difficulty of the topic. Based on classroom observations of existing practice, teachers used physical models both for demonstrations and student activities, but the use of Earth data was minimal. Based on student interviews and written assessments, students taught with existing practice have varying levels of understanding of correspondences and non-correspondences between model and Earth System at the levels of entities, configuration/motion, and causality/mechanism.

During a summer professional development workshop, we are introducing three instructional interventions: (a) activities to build awareness of higher level (configuration, motion, causality) correspondences and non-correspondences, (b) activities in which the model is used as a problem-solving tool, and (c) activities in which the behavior of the model is compared to Earth data. We will test the effectiveness of these new approaches during the 2011-2012 academic year.