The literature on science discourse in K–12 classrooms in the United States has proliferated over the past couple of decades, crossing geographical, disciplinary, theoretical, and methodological boundaries. There is general consensus that science talk is at the core of students’ learning; however, a synthesis of key findings from the expansive literature base is needed. This systematic literature review is guided by a complex systems framework to organize and synthesize empirical studies of science talk in urban classrooms across individual (student or teacher), collective (interpersonal), and contextual (sociocultural, historical) planes. Findings are discussed in relation to contemporary approaches that integrate theories and methodologies to account for the complex phenomena of science discourse, including interacting elements across levels as well as stable and changing patterns that influence students’ access to, and nature of, science talk in urban classrooms. Unresolved questions related to high-leverage, equitable, and sustainable discourse practices; future lines of inquiry that can benefit by drawing from diverse theoretical traditions and mixed methodological approaches; and practical implications for classroom-based strategies to support science discourse are also discussed.

在过去的几十年里，关于美国 K-12 课堂科学话语的文献激增，跨越了地理、学科、理论和方法的界限。普遍认为科学谈话是学生学习的核心；然而，需要综合大量文献库中的关键发现。这种系统的文献综述以复杂的系统框架为指导，以组织和综合城市课堂中跨越个人（学生或教师）、集体（人际）和情境（社会文化、历史）层面的科学谈话的实证研究。研究结果与当代方法相关，这些方法整合了理论和方法论以解释科学话语的复杂现象，包括跨级别的交互元素以及影响学生在城市课堂中获得科学讲座的机会和性质的稳定和变化的模式。与高杠杆、公平和可持续的话语实践相关的未解决问题；可以从不同的理论传统和混合的方法论方法中受益的未来探究路线；还讨论了支持科学话语的基于课堂的策略的实际意义。