Professional learning communities (PLCs) involve a process of collaboration, focus on student data and best instructional practices, and serve as a way for all students can receive an equitable education. Many schools implementing PLCs considered the term a noun, not a verb, leading to an inequitable education for high school students across campuses within the same district. This qualitative survey research explored the topics of conversations within PLC meetings, teachers' roles, focus during the sessions, and leadership within the PLC. Data were gathered from high school-only districts with district-wide PLCs in the Central Valley of California. The focus on PLCs comprised core areas identified as math, science, English, and social science. The courses studied within the core subjects were those considered graduation requirements. Purposeful and convenience sampling of the core teachers in the PLCs used for graduation requirements was employed. The study gathered survey data from the PLCs of Central Valley California high school-only school districts with multiple high schools and organized their PLCs by course. Data gathering and coding procedures were conducted using anonymous, open-ended questionnaires, and data analysis focused on identifying themes of topics of conversations during PLC meetings that will identify if a PLC is effective based on DuFour's characteristics. This study determined topics of conversation that identified PLCs as effective, such as student performance and sharing best practices. Due to minimal data, the effectiveness could not be determined by PLC, which means more research needs to be done to ensure all PLCs use their meeting time to focus on data-driven decisions and best practices for student achievement, which gives all students an equitable education. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]