Extended Reality (XR) combines dense sensing, real-time rendering, and close-range interaction, making its use in early childhood education both promising and high risk. To investigate this, we conduct a Systematization of Knowledge (SoK) of 111 peer-reviewed studies with children aged 3-8, quantifying how technical, pedagogical, health, privacy, and equity challenges arise in practice. We found that AR dominates the landscape (73%), focusing primarily on tablets or phones, while VR remains uncommon and typically relies on head mounted displays (HMDs). We integrate these quantitative patterns into a joint risk and attention matrix and an Augmented Human Development (AHD) model that link XR pipeline properties to cognitive load, sensory conflict, and access inequity. Finally, implementing a seven dimension coding scheme on a 0 - 2 scale, we obtain mean scholarly attention scores of 1.56 for pedagogy, 1.04 for privacy (primarily procedural consent), 0.96 for technical reliability, 0.92 for accessibility in low resource contexts, 0.81 for medical and health issues, 0.52 for accessibility for disabilities, and 0.14 for data security practices. This indicates that pedagogy receives the most systematic scrutiny, while data access practices is largely overlooked. We conclude by offering a roadmap for Child-Centered XR that helps HCI researchers and educators move beyond novelty to design systems that are developmentally aligned, secure by default, and accessible to diverse learners.

翻译：扩展现实（XR）融合了密集感知、实时渲染与近距离交互技术，使其在早期儿童教育中的应用既充满前景又具有高风险。为探究此问题，我们对111项涉及3-8岁儿童的同行评审研究进行了系统化知识综述，量化分析了技术、教学、健康、隐私及公平性挑战在实践中的具体表现。研究发现增强现实（AR）在该领域占据主导地位（73%），主要依托平板电脑或手机设备，而虚拟现实（VR）仍不普及且通常依赖头戴式显示器（HMD）。我们将这些量化模式整合至联合风险与关注度矩阵及增强人类发展（AHD）模型中，该模型将XR技术流程特性与认知负荷、感知冲突及资源获取不平等问题相关联。最后，通过实施七维度编码方案（采用0-2分制），我们获得以下学术关注度平均分：教学维度1.56分，隐私维度1.04分（主要集中在程序性同意），技术可靠性0.96分，低资源环境可及性0.92分，医疗健康问题0.81分，残障可及性0.52分，数据安全实践0.14分。这表明教学维度受到最系统的审视，而数据访问实践则基本被忽视。我们最终提出以儿童为中心的XR发展路线图，旨在帮助人机交互研究者与教育工作者超越技术新颖性，设计出符合发展规律、默认安全配置且适应多元学习者的系统。