Teachers’ confidence and facility with strategies that position and support students who are English learners (ELs) as active participants in middle grades mathematics classrooms are key to facilitating ELs’ mathematics learning. The Visual Access to Mathematics (VAM) project developed and studied teacher professional development (PD) focused on linguistically-responsive teaching to facilitate ELs’ mathematical problem solving and discourse. This study examines whether VAM PD has a positive impact on teachers’ self-efficacy in supporting ELs in mathematics and how components of the PD may have influenced teacher outcomes. Results from a field test involving a cluster randomized trial of 101 teacher participants from 47 schools showed that VAM PD had a positive impact on participants’ self-efficacy related to teaching ELs in mathematics, based on pre/post self-efficacy survey responses. An analysis of participants’ written reflections suggests that supported implementation of language strategies with ELs in their mathematics teaching contexts was a key PD component that contributed to teacher self-efficacy outcomes. Findings offer implications for mathematics teacher PD and for facilitating ELs’ learning in mathematics.

教师的信心和设施以及采取策略来定位和支持英语学习者（EL）的学生，使其成为中级数学课堂的积极参与者是促进ELs数学学习的关键。“视觉访问数学（VAM）”项目开发并研究了教师专业发展（PD），着重于语言响应型教学，以促进EL的数学问题解决和论述。这项研究调查了VAM PD是否对教师支持数学中的EL的自我效能产生积极影响，以及PD的组成部分如何影响教师的成绩。一项来自47个学校的101名教师参与者的整群随机试验的现场测试结果表明，VAM PD对与数学中的EL教学相关的参与者的自我效能有积极影响，根据之前/之后的自我效能感调查回复。对参与者的书面思考的分析表明，在他们的数学教学环境中支持EL实施语言策略是PD的关键组成部分，它有助于提高教师的自我效能感。研究结果对数学老师PD以及促进EL的数学学习具有启示意义。