Professional learning communities (PLC) have been identified as scaffolds that can facilitate, support, and sustain systemic change focused on improving student achievement. PLCs represent the application of the theoretical constructs of the learning organization within the framework of schools and school systems. Little is known about the change process that comprehensive suburban high schools undergo as the attempt to develop and implement PLCs. The purpose of this study was to examine teachers' and administrators' perceptions of the change process that is occurring in their schools as they implement PLCs. The study intended to identify common experiences and barriers, as well as identify and generalize the process associated with developing a PLC in comprehensive high school settings. Data were collected using a demographic questionnaire, the Stages of Concern (SOC) survey, and the School Professional Staff as Learning Community Questionnaire (SPSLCQ). A total of 149 educators in four comprehensive suburban high schools participated in the study. The findings of this study indicated that the lower stages of concern as measured by the SoC were correlated in a negative direction with the five subscales measured by the SPSLCQ. The highest stage of concern, refocusing, also was correlated with the five subscales of the SPSLCQ. Time that staff had been collaborating as a PLC moderated the relationship between the awareness Stage of Concern and the SPSLCQ scale of; staff shares vision for school improvement. The relationship between the informational Stage of Concern and the SPSLCQ scale; school conditions and capacities support the staff's engagement was also moderated by the time that staff had been collaborating as a PLC. The relationship between the more advanced stages of concern and the scales of the SPSLCQ were not moderated by time that staff had been collaborating as a PLC. The findings of this study indicate that additional professional development is needed to help teachers and administrators understand the purpose for collecting and analyzing data need to support instructional changes that could lead to improved student academic outcomes. [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.]