Driven by Race to the Top funding and quickly designed and deployed in 2010-2011, a new teacher evaluation policy in Tennessee altered principals' supervisory practices regarding their use of time for observation and reporting, their interaction with teachers, and the methods for giving teachers performance ratings. In addition, student test score data were integrated into final ratings, and professional consequences were linked with those ratings. Researchers in this study followed fourteen school principals over a five-year period to understand how their perceptions of new evaluation policy components affected their implementation. Data were analyzed using the structural and human resource frames of Bolman and Deal (2017) to interpret policy demands, principals' perceptions, and variations in implementation. Findings indicate that principals appeared to reject strict application of the policy's structurally focused components and procedures, while supporting collaborative, human resource-oriented approaches for promoting teacher growth and professional development.