Developing a Research-Based Learning Progression for the Carbon Cycle: Transformations of Matter and Energy in Biogeochemical Systems

这个项目将研究学习进程的发展：基于旧的和新的研究，对学生关于碳在环境系统中的作用的推理的发展进行连贯的描述。碳在环境系统中的作用包括物质的物理和化学变化、动植物的生长和衰退、光合作用和细胞呼吸、生态系统中的物质循环和能量流动，以及人类和人类技术对这些过程的影响。本项目的成果将包括：1.对儿童学习的纵向描述，记录了通过高中生概念理解和运用这些知识的能力在小学发展中的链条。这一说明将部分基于对现有研究的综合，包括PI项目和顾问所做的研究。该项目将在先前工作的基础上进行新的研究，填补空白，并对跨越主要亚组的美国学生样本进行验证。2.经过验证的评估，衡量学生在小学、初中和高中阶段对生物地球化学系统中物质和能量转化的理解。评估系统基于儿童学习的纵向描述中定义的进度变量。该系统将包括用于教室的嵌入式评估和构成系统设计的大规模评估计划的基础的链接测试。这些评估将用于对农村、城市和郊区教室中的学生推理进行调查。这些评估将通过BEAR评估系统提供给大型评估开发人员和课堂教师。有报道称，在资源丰富的教室里，当学生遇到有关环境系统的挑战性问题时，教学实验侧重于学生的推理。这些报告将捕捉学习的动态--既有掌握关键概念工具和实践的学生成功的学习，也有成功学习的障碍。教学实验将在农村、城市和郊区的小学、初中和高中阶段的教室中进行。

This project will study the development of a learning progression: a coherent account of the development of students' reasoning about the role of carbon in environmental systems, based on old and new research. The role of carbon in environmental systems includes physical and chemical changes in matter, growth and decay of plants and animals, photosynthesis and cellular respiration, matter cycling and energy flow in ecosystems, and the effects of humans and human technologies on these processes. Products of this project will include:1. A longitudinal description of children's learning that documents strands in the development of elementary through high school students' conceptual understanding and ability to use this knowledge. This account will be based in part on a synthesis of existing research, including research done by the project PI's and consultants. The project will conduct new research that builds on prior work, fills in gaps, and validates findings for a sample of American students that spans major subgroups. 2. Validated assessments that measure student understanding of matter and energy transformations in biogeochemical systems at the upper elementary, middle school, and high school levels. The assessment system is based on progress variables defined in the longitudinal description of children's learning. The system will include both embedded assessments for use in classrooms and link tests that form the basis of a systematically designed large-scale assessment program. These assessments will be used for a survey of student reasoning in a sample of rural, urban, and suburban classrooms. The assessments will be made available to large-scale assessment developers and classroom teachers through the BEAR Assessment System.3. Reports of teaching experiments focusing on students' reasoning when they encounter challenging questions about environmental systems in resource-rich classrooms. These reports will capture the dynamics of learning-both successful learning by students who master key conceptual tools and practices and barriers to successful learning. The teaching experiments will be conducted in rural, urban, and suburban classrooms at the upper elementary, middle, and high school levels.