|A growing number of policymakers are searching for new approaches to identify good teaching, promote it, and reward it. In the birth-to-five world, many states have developed Quality Rating and Improvement Systems (QRIS) that identify, rate, and enhance the quality of programs based on a wide array of criteria, such as adult-child ratios and how well teachers respond to children’s needs. In the K-12 world, states are trying to identify good teaching at the level of the individual teacher. Observation tools should play a significant role in the development of these evaluation and professional development systems. This policy brief makes recommendations to federal and state governments, as well as teacher preparation programs and researchers, to establish fair and reliable measures of teachers’ practice.