The purpose of this multi-site study is to gain an understanding of what practices principals are employing that are impacting the effectiveness of the instructional coaches, as measured by student achievement on end of year state assessments. This study looked at three Tier 3 schools in Miami Dade County Public Schools (MDCPS) that showed significant improvement in student achievement as measured by the statewide assessments. Tier 3 schools are schools in MDCPS that have been identified by the Florida Department of Education as consistently underperforming. This dissertation sought to understand what practices were implemented by the principals in these schools that the instructional coaches considered supportive of their instructional coaching. The study participants consisted of 3 principals, 3 assistant principals, 3 coaches, and 3 teachers, for a total of 12 participants. The assistant principals were interviewed because they are tasked with supervising various content areas and as such work directly with the coaches. The teachers were interviewed because the role of coaches is to work directly with the teachers, therefore the teachers have insight into their effectives. The participants were asked to reflect on their experience either as an instructional coach or working with the instructional coach. They participated in a 30-to-45-minute interview. Additionally, the school improvement plans, and coaching logs were analyzed. The findings revealed that principals did not consider data literacy as a crucial component when hiring a coach. All the coaches shared that they deepened their knowledge of data once they were in the coaching role. The study found that content knowledge and collaboration were important components of effective coaching. The coaches indicated that while they do attend professional developments provided by the district, the majority of their knowledge is acquired through on the job training. The coaches specifically identified support from assistant principals that were former coaches, as instrumental. Additionally, the study found that when hiring an instructional coach, principals place more value on finding an individual that is the "right-fit." All the participants indicated that they really valued trust. Whether it was the principal being able to trust the coaches, the teachers being able to trust the coaches, or the coaches feeling valued because of the trust placed in them. All the schools had built in collaborative planning for the various content areas, which was utilized as an opportunity to foster relationships in addition to planning lesson and professional developments. Lastly, participants at all the school sites described the culture of their school as a family, which contributed to the positive relationships among students, teachers, coaches, and administrators in the building. [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://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]