School leaders serving a school identified as high-poverty often face unique stresses and pressures to increase gains in student achievement, often in a relatively short amount of time. Leaders will make decisions to change the instructional framework or design of a school in hopes of meeting such pressure. There is abundant research that has begun to emerge that leadership effectiveness perception surveys are vital for a leader to monitor several aspects of the school. School leaders who make such a decision without seeking teacher voice face a problem with teachers' perceptions of leadership effectiveness. A variety of reason exists for this problem leaders face, including not seeking teacher voice and not discussing the change to the instructional framework prior to implementation. Since classroom teachers are the main sources responsible for improving student performance, there is a high importance in understanding their lived experience in implementing a mandated instructional change. In this qualitative phenomenological study, interviews with teachers in the same elementary school were conducted. Participants who were employed at the school prior and during the implementation of a new, innovative instructional framework were purposefully selected in order to gain rich, textual data regarding the lived experiences of teachers in implementing a mandated instructional change. Results of the study indicated that leadership effectiveness is negatively perceived when teachers were ignored and not given a vice or proper background information with the new instructional model. The findings imply that school leaders should develop a sound process before, during and throughout an instructional change to ensure that teachers are valued for their expertise and opinions. [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.]