Understanding how chemistry teachers' interventions shape the reasoning that students express after a lesson is critical to support prospective and in-service teachers as they work with students' ideas in the classroom. In this qualitative research study, we analysed changes in the reasoning expressed by 10th grade students in a Chilean school in their written explanations about freezing point depression before and after a lesson on the topic. We also investigated how the teacher's interventions shaped the type of reasoning expressed by participating students. Our findings revealed significant shifts in the types of explanations generated after the lesson. A significant number of students transitioned from relational to simple causal reasoning in their pre- and post-lesson explanations. After the lesson most of the explanations were based on the activities of one or more of the system's entities. Analysis of teacher–student interactions during the observed lesson suggests that the teacher's mediation played a central role in the shift towards simple causal reasoning with centralized causality that was observed. The teacher in our study was more skilled at eliciting students' ideas than at helping students develop them with proper scaffolding. Thus, the observed classroom talk could not be considered as accountable talk, as most of the key ideas were introduced, selected, or reshaped by the teacher.

中文翻译：

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调查教师调解对学生表达的推理的影响

了解化学老师的干预如何塑造学生在课后表达的推理，对于支持准教师和在职教师在课堂上处理学生的想法时至关重要。在这项定性研究中，我们分析了智利学校10年级学生在关于该主题的课前和课后对冰点降低的书面解释中表达的推理变化。我们还调查了教师的干预如何影响参与学习的学生所表达的推理类型。我们的发现表明，课后产生的解释类型发生了显着变化。大量的学生在课前和课后解释中从关系因果推理转换为简单因果推理。上课后，大多数解释都是基于系统中一个或多个实体的活动。对观察到的课程中师生互动的分析表明，教师的调解在向简单的因果推理转变为集中因果关系的过程中发挥了核心作用。我们研究中的老师更能激发学生的想法，而不是帮助学生通过适当的脚手架发展他们的想法。因此，观察到的课堂谈话不能被视为负责任的谈话，因为大多数关键思想是由教师介绍，选择或重塑的。调解在向简单的因果推理转变为集中因果关系的过程中发挥了核心作用。我们研究中的老师更能激发学生的想法，而不是帮助学生通过适当的脚手架发展他们的想法。因此，观察到的课堂谈话不能被视为负责任的谈话，因为大多数关键思想是由教师介绍，选择或重塑的。调解在向简单的因果推理转变为集中因果关系的过程中发挥了核心作用。我们研究中的老师更能激发学生的想法，而不是帮助学生通过适当的脚手架发展他们的想法。因此，观察到的课堂谈话不能被视为负责任的谈话，因为大多数关键思想是由教师介绍，选择或重塑的。