The purpose of this case study was to investigate staff perceptions of a shared leadership framework embedded in a school's turnaround improvement intervention model and the factors of that model perceived to contribute to growth in student achievement. Thirty-one staff members participated in this mixed-method study by responding to the Distributed Leadership Readiness Scale (DLRS) survey instrument and open-ended written response questions. Focus group interviews were then conducted with randomly selected participants to triangulate evidence around factors of a shared leadership framework perceived to have affected student achievement. Of the 31 responders, 22 or 71% were teachers, and 9 or 29% were instructional support staff. Analysis of the data revealed teacher and staff support for the purposeful development of reciprocal professional relationships among staff and administration, and the use of instructional best practices by teachers and teacher leaders contributing to a positive school culture and improved student achievement. Findings from the data revealed developing a school culture that empowers teachers to be a part of a shared decision-making process, in both formal and informal leadership roles, for instructional improvement to support student achievement, was an area of success and an area needing continued improvement at the focus school. The research findings could guide other schools in improvement initiatives when they are navigating the systemic changes needed for equitable student growth and improved achievement in their school systems. [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.]