Early childhood assessments can provide important information to guide instruction and inform policy. Given the widespread and growing use of statewide kindergarten entry assessments (KEAs), in particular, it is important that policymakers understand how to choose and use assessments wisely. This brief summarizes research showing how authentic assessments grounded in guided observation and well-chosen performance tasks can be used to chart children’s progress in multiple domains of development and inform instruction. It provides recommendations for state policymakers about how to select, develop, and implement high-quality assessments that can both support instruction and inform policy to improve systems. (author abstract)