There is strong agreement in science teacher education of the importance of teachers' content knowledge for teaching (CKT), which includes their subject matter knowledge and their pedagogical content knowledge. However, there are limited instruments that can be easily administered and scored on a large scale to assess and study elementary science teachers' CKT. Such measures would support strategic monitoring of large groups of science teachers' CKT and the investigation of comparative questions about science teachers' CKT longitudinally across the professional continuum or across teacher education or professional development sites. To address this gap, this study focused on designing an automatically scorable summative assessment that can be used to measure preservice elementary teachers' (PSETs') CKT in one high-leverage science content area: matter and its interactions. We conducted a field test of this CKT instrument with 822 PSETs from across the United States and used the response data to examine how this instrument functions as a potential tool for measuring PSETs' CKT in this science content area. Results suggest this instrument is reliable and can be used on large scale to support valid inferences about PSETs' CKT in this content area. In addition, the dimensionality analysis showed that all items measure a single construct of CKT about matter and its interactions, as participants did not show any differential performance by content topic or work of teaching science instructional tool categories. Implications for progressing the field's understanding of the nature of CKT and approaches to developing summative instruments to assess science teachers' CKT are discussed.

中文翻译：

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开发和使用可扩展的评估来衡量职前小学教师的物质教学内容知识

科学教师教育界普遍认同教师教学内容知识（CKT）的重要性，其中包括他们的学科知识和教学内容知识。然而，能够轻松管理和大规模评分以评估和研究基础科学教师 CKT 的工具有限。这些措施将支持对大量科学教师的 CKT 进行战略监测，并支持在整个专业连续体或跨教师教育或专业发展领域纵向调查有关科学教师 CKT 的比较问题。为了解决这一差距，这项研究的重点是设计一种自动评分的总结性评估，可用于衡量职前小学教师 (PSET) 在一个高杠杆科学内容领域的 CKT：物质及其相互作用。我们对来自美国各地的 822 个 PSET 对该 CKT 仪器进行了现场测试，并使用响应数据来检查该仪器如何作为测量该科学内容领域 PSET CKT 的潜在工具。结果表明，该工具是可靠的，可以大规模使用，以支持有关该内容领域的 PSET CKT 的有效推论。此外，维度分析表明所有项目都测量关于物质及其相互作用的 CKT 单一结构，因为参与者在科学教学工具类别的内容主题或工作方面没有表现出任何差异表现。讨论了促进该领域对 CKT 本质的理解的意义以及开发评估科学教师 CKT 的总结性工具的方法。