This three-article dissertation contains three approaches to the topic of professional learning communities and their impact on student achievement. Article I is a synthesis of the literature related to the purpose of professional learning communities. Implications in educational settings are also presented in this article. The context of the review acknowledges the role of constructivism as the theoretical basis for the participation of teachers in professional learning communities, and highlights the significance of the problem. Article II describes a qualitative case study which explores data collected from teachers (via survey, N=35) and administrators (via in-person interviews, N=3) about the implementation and impact of a professional learning community at an underperforming school. Article III provides a training manual that may be utilized to revise and expand a pilot model of professional learning communities in an elementary school.