The aim of this proposal is to expand knowledge about the predictive validity of the ECERS-3 tool used in the context of QRIS ratings. To accomplish this, data from the Large Scale Psychometric Assessment of the ECERS-3 study will be linked with data from the Quality Compendium, which compiles data on each QRIS in the U.S. The purpose of linking these datasets is to simulate QRIS ratings using ECERS-3, CLASS, and other available quality indicators and to examine the predictive validity of simulated QRIS ratings with children’s outcomes. Outcomes of interest include preschoolers’ growth over the course of the year in expressive language, pre-literacy skills, mathematical reasoning, behavioral regulation, social- emotional well-being, and health status. This proposal addresses gaps and extends previous research on the ECERS-3 tool in two important ways: (1) by examining the categorical cut- scores for ECERS-3 that maximally retains the tools’ association with children’s outcomes and (2) by evaluating methods for combining ECERS-3 scores with CLASS scores and other quality indicators, as is done in many QRIS, to predict children’s outcomes more robustly. (author abstract)