This qualitative study explores the experience of specialist teachers specific to their individual roles within the coaching model (CM). Reasons for in-depth study include (a) Rochester's struggle to meet federal and state student achievement benchmarks, (b) practitioner frustrations from site-level resistance or CM use, and (c) shifting role expectations for those trained in CM use. The study focuses on CM use by specialist teachers in an upstate New York district. Targeting contrasts among their perceptions, understandings, and assumptions, the main idea is that maximum teacher professional development requires on-going critical understanding of coaching progress. With a data set of semi-structured responsive interviews of nine study participants, grounded theory protocol involves constant immersion into the data. Key findings include (a) more critical understanding of CM application and related assumptions may improve, if not maximize, instructional coaches as professional development resources; (b) school culture conditions help to gauge the progress schools can and do achieve using reform strategies such as coaching; and (c) specialist teachers' understandings and assumptions may provide a trustworthy means of monitoring how different school cultures view coaching. Study recommendations include (a) improving how schools use coaches as on-site professional development resources, (b) preparing principals to be attuned to the big picture of the CM's potential for improving teaching, and (c) continuing to improve coaches' capacities to navigate the developing cultural contexts in which they work. [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.]