In this "Fast Facts," a state has received Race to the Top Early Learning Challenge funds and is seeking information to inform the design of the Quality Rating and Improvement System (QRIS) validation study. The Center on Enhancing Early Learning Outcomes (CEELO) responds that according to Resnick (2012), validation of a QRIS is an "ongoing, iterative process that assesses whether design decisions about program quality standards and measurement strategies are producing meaningful and accurate ratings". QRIS validation studies can determine whether rating components and summary ratings can be relied on as ac-curate indicators of program quality, and can produce recommendations to improve the system. The validation studies that states have conducted or are currently conducting can be grouped into four different categories: (1) Examination of underlying concepts; (2) Examination of the psychometric properties of measures used to assess quality; (3) Assessment of outputs of the rating process; and (4) Relation of ratings to expected child outcomes. Herein, each of these categories is discussed and a list of related resources and links is provided.