A Systematic Review of Research Designs Used to Evaluate State and Locally Funded Pre-K Programs

August 2026

Expansions of state and locally funded pre-k programs in recent decades have been promoted by advocates citing strong research support. However, questions have been raised about how supportive the research base actually is. We conducted a systematic review of pre-k evaluation studies (from 2000-2021) to document their research designs and the direction of their reported impacts. Most of the 120 evaluation reports identified came from 91 studies that used designs lacking internally valid comparisons between pre-k attenders and comparison children. The direction of achievement effects assessed at the end of pre-k was overwhelmingly positive, regardless of research design. At the same time, the direction of longer-term achievement effects varied by research design. Specifically, 65% of the estimates from randomized evaluations were negative in direction, compared with between 16% and 25% of estimates based on other designs. Our findings point to an urgent need for more rigorous research on pre-k effectiveness, particularly from studies using randomized designs, to investigate longer-term effects.

Keywords

Systematic Review, Pre-Kindergarten Programs, Early Childhood Education

Education level

K-12 Education

Topics

Student Learning