The purpose of the study was to examine teacher perceptions of school process data over time to determine whether No Child Left Behind (NCLB) sanctions and interventions might produce any observable change in teachers' perceptions of the selected school processes. This study examined the relationship between the school's NCLB sanction status and teachers' perceptions of school organizational cohesiveness in three key dimensions. The study employed time-series design with a piecewise linear growth model analysis of teacher perceptions in a baseline set of schools that did not enter NCLB sanctions over the period of the study (and teacher perceptions of those processes in schools before they entered sanctions) against a set of schools that entered sanctions during the course of the study. The study provided both methodological and substantive contributions to research on school improvement. The primary methodological contribution was the use of a piecewise linear growth model analysis to measure the changes in perceptions resulting from school reform policy initiatives over time. Most prior studies available used qualitative or mixed methods analyses when examining school reform implications. The results demonstrated that seemingly slight increases or decreases at a single event can reveal a significant trend when analyzed across a series of related events. The substantive contribution of the study was the confirmation that teacher perceptions of school organizational cohesiveness were influenced when a school entered NCLB imposed sanctions. In this study, decreases in teachers' perceptions of Shared Leadership in conjunction with schools entering sanctions were identified. Of primary concern was the evidence that teachers' positive perceptions of Shared Leadership suffered under NCLB sanctions. Increased variability of the proportions of positive responses between those schools was demonstrated for Shared Leadership and Professional Development. The increased variation in Professional Development suggested that entering sanctions had neither a consistently positive nor a consistently negative influence on professional development at the schools. Instead, it suggested that the professional development at the schools varied considerably in concept and delivery. Furthermore, the results suggested that school organizational cohesiveness is disrupted when a school enters sanctions as demonstrated by the increased variation in responses for two dimensions. [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.]