Evaluation policies set an important frame of reference for how evaluations are implemented. Despite the central influence that policies play in how evaluations are conducted, little empirical work has been conducted to better understand how these policies are interpreted and implemented. This paper describes the findings of case study evaluation designed to examine the implementation of a California State evaluation policy that required grantees to conduct scientifically based research of their improving teacher quality projects. Study findings point to variation in individuals' perceptions of what constitutes high-quality SBR and the extent to which they felt that SBR should be conducted in their specific settings. Other findings point to opportunities for increasing the role of formative evaluation within these projects. (Contains 1 figure and 2 tables.)