We examined the sophistication of middle school students’ mechanistic explanations of genetics phenomena and how they interact with a technology-based explanation tool as they articulate and organize their ideas about the phenomena. We coordinated curriculum and assessment design frameworks to develop a middle school curriculum unit that engages middle school students in the interrelated science practices of using models and constructing scientific explanations of the trait expression mechanism in rice plants. In order to more clearly distinguish between groups of students, specifically partial mechanistic and mechanistic explainers, we conducted a design-based research study that examines the relationships among the explanation tool’s design, how students use the tool, and the sophistication of their scientific explanations. This study, using a refined version of the curriculum unit and explanation tool, revealed significant differences between partial mechanistic and mechanistic explainers in their use of the explanation tool. The findings inform the design of technology-based scaffolds for scientific modeling and explanation and design principles for gathering formative evidence of students’ proficiency with these practices.

中文翻译：

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技术查询中的中学生对水稻植株性状表达的机理解释

我们研究了中学生对遗传现象的机械解释的复杂程度，以及他们在表达和组织有关现象的想法时如何与基于技术的解释工具进行交互。我们协调了课程和评估设计框架，以开发一个中学课程单元，使中学生参与相互关联的科学实践，这些实践涉及使用模型和构建水稻植株性状表达机制的科学解释。为了更清楚地区分学生，特别是部分机械学和机械学解释者，我们进行了一项基于设计的研究，研究了解释工具的设计，学生如何使用工具以及科学解释的复杂程度之间的关系。这项研究，使用课程单元和解释工具的精简版本，发现部分机械解释员和机械解释员在使用解释工具方面存在显着差异。研究结果为基于科学的脚手架的设计提供了科学建模，解释和设计原则，以收集学生对这些实践的熟练程度的形成证据。