'I have a connection!': The situated sense-making of an elementary student about the role of water in modeled vs. experienced ecosystems.

摘要

Current policy and research have led the field of science education towards a model of "science as practice." In the past decade, several research programs on model-based reasoning practices in education have articulated key dimensions of practice, including constructing and defending models, comparing models to empirical data, using representations to identify patterns in data and use those as inscriptions to buttress arguments.;This study presents a detailed case of how the use of a physical microcosm and children's self-directed representations of an ecosystem constrained and afforded student sense-making in an urban elementary classroom. The case analyzed the experiences of a 10-year old fifth grade student, Jorge, and the variation in his expressed understanding of ecosystems as he interacted with academic tasks, along with models and representations, to design, observe and explain an ecological microcosm. The study used a conceptual framework that brings together theories of situated cognition and Doyle's work on academic task to explain how and why Jorge's perception and communication of dimensions of ecosystem structure, function, and behavior appear to "come in and out of focus," influenced by the affordances of the tools and resources available, the academic task as given by the teacher, and Jorge's own experiences and knowledge of phenomena related to ecosystems.;Findings from this study suggest that elementary students' ability or inability to address particular ecological concepts in a given task relate less to gaps in their understanding and more to the structure of academic tasks and learning contexts. The process of a student interacting with curriculum follows a dynamic trajectory and leads to emergent outcomes. As a result of the complex interactions of task, tools, and his own interests and agency, Jorge's attunement to the role of water in ecosystems comes in and out of focus throughout the unit. The instructional constraint of needing to integrate the FOSS Water Cycle curriculum into the Bottle Biology Project became an affordance for Jorge to ask questions, observe, and theorize about the role of water and the water cycle in an ecosystem. The practice of modeling a closed ecosystem made salient to Jorge the boundaries of a system and the conservation of water within that system. The closed ecosystem model also presented constraints to students' sense making about the role of interactions when students lack domain knowledge in ecology. Relying on students' own talk, photographs and representations as explanations of phenomena in the Bio Bottle, without establishing norms of representational conventions and communication, resulted in missed opportunities for Jorge to reinforce his sense making during the activity and to develop conventions of scientific representation. Findings from this study can be used to inform the design and implementation of learning environments and curricular activities for elementary and middle school students that address all three dimensions of the Next Generation Science Standards: a) developing conceptual understanding of key concepts in the domain of ecology, b) the cross-cutting concept of systems, and c) multiple practices that ecologists use in developing and evaluating models that explain ecosystem structures, functions, and change over time.