Abstract

Professional development for teachers is regarded as one of the principal pathways through which we can understand and cultivate effective teaching and improve student outcomes. A critical component of studies that seek to improve teaching through professional development is the detailed assessment of the intermediate teacher development processes that scaffold program content through three key types of outcomes—teacher knowledge, instruction, and student learning. Cross-level and sequential mediation strategies that probe and connect these processes and outcomes emerge as an important design consideration in these studies. We derive formulas that track the power with which school-randomized designs can detect professional development effects as they operate through a sequence of teacher-level mediators to affect student outcomes (e.g., school-randomized professional development studies). The results suggest that the sample sizes typically seen in well-planned experiments targeting total effects (e.g., 30–100 schools) can produce comparably high or disparately low levels of power for mediation effects—the similarity depends heavily on context and concomitant parameter values. The results are implemented in the PowerUpR package and in the PowerUpR Shiny application.

摘要

教师的专业发展被认为是我们了解和培养有效教学并改善学生成果的主要途径之一。旨在通过专业发展来改善教学的研究的重要组成部分是对中级教师发展过程的详细评估，该过程通过三种关键类型的结果（教师知识，指导和学生学习）来支持课程内容。探究和联系这些过程和结果的跨层次和顺序调解策略在这些研究中成为重要的设计考虑因素。我们推导了公式，这些公式跟踪学校随机设计通过一系列教师级调解员运作以影响学生成果的能力（例如，学校随机的专业发展研究）。结果表明，在针对总体效果（如30至100所学校）的精心计划的实验中通常可以看到的样本量可以产生相对较高或相对较低的中介作用力-相似度在很大程度上取决于环境和相应的参数值。结果在PowerUpR软件包和PowerUpR Shiny应用程序中。