This mixed methods study was conducted to investigate the impact the knowledge, skills, dispositions, and coaching style of an instructional coach has on middle grades teacher instructional practices. The results of this study can be used to inform school leaders, administrators, and instructional coaches on methods for improving instructional coaching practices. The study was conducted utilizing a survey instrument and interviews. The survey indicated the instructional coaches have a role in developing instructional practices, though the qualitative data indicated possibility of greater impact than in current practice. Interview participants identified opportunities for a greater impact, such as incorporating timely, balanced, and concrete feedback, as well as a call for increased visibility in the classrooms. Survey responses showed teachers believe instructional coaches have the requisite knowledge of content, teaching, and curriculum to effectively coach, though a weakness was in instructional coaches having the ability to effectively coach teachers teaching outside of the content area the instructional coach had previously taught in. [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.]