Once is partnering with Johns Hopkins University on a multi-year randomized controlled trial (RCT) — one of the most rigorous research designs available — to measure the impact of Once on kindergarten reading outcomes.
Districts joining the study in 2025–26 include Wentzville, Aiken, and Spartanburg School District 7, with more to follow.
This brief explains the randomization design, timeline, and how districts and schools are matched into treatment and control groups to produce causal evidence about Once’s effect on student reading growth.
Stay tuned for interim findings — and get in touch if you’d like to learn more about participating in future RCT cohorts.