It is a common knowledge that student achievement is a product of multiple individual and environmental factors. The literature developed various models to organize and explain the relationship between some of these variables and student learning which translates into student achievement. Yet, no comprehensive model is able to capture all possible…

Objectives: Group-randomized designs are well suited for studies of professional development because they can accommodate programs that are delivered to intact groups (e.g., schools), the collaborative nature of professional development, and extant teacher/school assignments. Though group designs may be theoretically favorable, prior evidence has…