This study of a suburban school district in south central Pennsylvania employed a mixed method design to explore teachers' perceptions of their professional learning community (PLC) and the impact of such on teaching effectiveness and student learning. Perceptual data was collected through the Learning Community Culture Indicator (LCCI) teacher survey and extended through focus group interviews. The findings of this study confirm that teachers in the district perceive PLCs to impact teaching effectiveness and student learning. The statistical data of the LCCI survey indicated teachers held a positive perception of PLC implementation in their school especially in the elements of common mission, vision, values, and goals focused on teaching and learning; data based decision-making using continuous assessment; principal leadership focused on student learning; and interdependent culture based on trust. The analysis of the qualitative data further revealed that teachers do perceive the PLC model to impact teaching effectiveness and student learning through reflection and collaboration regarding student learning as well as continuous monitoring of student learning for continuous improvement. Examining teachers' descriptions and stated beliefs concerning PLCs and the perceived relationship to teaching effectiveness and student learning allowed a deeper understanding of the complex conditions unexplored in the literature. These additional insights serve to extend the literature and provide further information regarding the study topic. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://www.proquest.com/en-US/products/dissertations/individuals.shtml.]