The present study investigated the district-wide characteristics of relational ties among a sample of K-12 teachers implementing the Common Core comprehensive education reform. This study addressed deficits in current scholarly understanding of the social influences in schools that impact delivery of educational reform efforts such as the Common Core by utilizing social network analysis to conduct descriptive and inferential examinations of teachers' self-reported interactions in three domains: Common Core lesson planning, student assessment related to the Common Core, and non-professional social ties. In particular, this study focused on the role of professional learning communities (PLCs) within the district in contributing to a) the formation of relational ties among teachers and b) reform-relevant teacher outcomes. Preliminary analyses revealed low levels of overall advice-seeking behavior at the district level across three domains. Descriptive social network analyses at the individual and PLC levels revealed variation across participants and groups, respectively, in the number of relational ties among teachers. Using multilevel regression modeling for main study analyses, characteristics of teacher ties at the individual and PLC levels were examined in relation to teacher-level outcomes related to the Common Core, namely: Common Core buy-in; self-efficacy for instruction; alignment of curriculum, instruction, and assessment to state standards; perception of the learning environment within the district as supportive; and focused professional development related to the reform. Findings indicate limited support for the role of PLCs in contributing positively to teacher-level dependent variables, despite considerable time and resources used to fund this professional development model. Results indicate a need to further examine the relationship between teacher interactions within PLCs and teacher-level dependent variables (e.g., instructional practice and student performance). [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]