This mixed-methods study investigates the effect of differentiated phonics lessons on reading fluency and examines the effect of these lessons on student and teacher perceptions of school culture. The study examines quantitative data on the effectiveness of the skill lessons. The qualitative findings examine the impact of the lessons on the dynamics of school culture as perceived by students and teachers given the opportunity to interact with wider and varying school groups. The understandings gained from the combination of the quantitative and qualitative data interpret the effect of the structure of differentiated across grade-level lessons on school culture. [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.]