This study examined how principals in eight high-functioning elementary schools provide teacher supervision and evaluation to promote high levels of student achievement. Perceptions of teachers were measured to provide an understanding of which specific principal behaviors translated into better instructional practices within the selected schools. Schools were chosen based on their performance on both state communication arts and math standardized assessments, which were in the top 10% of all elementary schools in the state. Data were collected from 74 teachers using an online survey tool to assess perceptions about principals' supervision within pre-observation and post-observation conferences. Quantitative analyses, part of a larger inquiry previously analyzed by the authors, revealed that 64% percent of the variability in principals' pre-conference supervisory effectiveness was accounted for by discussing how students will be engaged in their learning during instruction; 65% of the variability in principals' post-conference supervisory effectiveness was accounted for by building teachers' capacity to self-reflect about teaching. Overall, this study points toward the importance of teachers and principals working together to provide engaging instruction to drive increased student achievement while implementing school reform and improvement efforts.