From the report: "In this report, we use test score results from roughly 8,000 school districts in 30 states to measure the extent to which test scores changed from Spring 2019 to Spring 2022 and from Spring 2022 to Spring 2023. We use methods developed by Reardon and colleagues to put the test scores from each state’s tests onto a common scale and to convert proficiency rates to “grade levels” of achievement (Reardon, Kalogrides, & Ho, 2021; Reardon, Shear, Castellano, & Ho, 2017). This allows us to measure changes in test scores between 2019 and 2023 on a common, interpretable scale for all school districts in these 30 states, despite the fact that they use different tests and proficiency thresholds. Using these detailed data, we report 1) the extent of academic recovery for each of the 30 states; 2) the extent to which the 2019-2022 losses and 2022-2023 improvements varied across school districts; and 3) how these patterns varied by district poverty rates and by student racial and economic background."