As one set of responses to the increasing demands of adequate yearly progress exerted by the No Child Left Behind Act, schools have been using professional learning communities as a tool to improve academic performance. The researcher conducted this descriptive quantitative study to query principals from 40 high- and 40 low-performing elementary schools, identified in the 2006 Similar School Ranking of the California Academic Performance Index, in a select county of California to determine perceptions concerning (a) how their schools compared to Senge's five components of a learning community, including personal mastery, shared vision, mental models, team learning, and systems thinking; and (b) whether there was a statistical difference between perceptions of principals from high- and low-performing schools about their schools as learning communities. This study was modeled on Dougherty's study of elementary principals in an urban county, which was chosen to be replicated to discover whether similar results could be obtained in a rural demographic. The survey results were collected and scored in relationship to Senge's components. Both the high- and low-performing met some of the criteria; the high-performing schools were more closely aligned than the low-performing schools. Further, t-tests showed that there was a significant difference between perceptions of principals of high- and low-performing schools in that the high performing schools were more likely to be functioning as professional learning communities. This study may influence social change by providing further insight to principals and administrators about the academic benefits of creating a professional learning community to improve student achievement. [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.]