Skip to Main Content


New research on the effects of preschool dosage and instructional alignment on child outcomes

August 31, 2021
by Michael Strambler and Joanna Meyer

PEER enthusiastically supports the current presidential administration’s proposal to make high-quality preschool accessible to all 3- and 4-year-olds as part of the American Families Plan. But what should universal preschool look like? Much of the research demonstrating the long-term benefits of high-quality preschool on children’s outcomes is based on three model preschool programs that are difficult to replicate: Carolina Abecedarian Project/Carolina Approach to Responsive Education (ABC/CARE), Perry Preschool Project, and Chicago Child-Parent Centers. As the nation thinks seriously about expanding access to preschool for 3- and 4-year-olds, it is important for research to improve our understand of the structures and processes that are most likely to contribute to students’ success.

Two important research topics are understanding the benefits of one versus two years of preschool and how to align preschool with kindergarten curricula. These were the two issues taken on in a panel at the biennial meeting of the Society for Research in Child Development (SRCD) earlier this year where PEER’s Director, Dr. Michael Strambler, was a discussant. Dr. Jessica Harding of Mathematica Policy Research presented research that used Head Start data to compare the relative gains of two cohorts: first year students and returning students. She found that although both cohorts of child experiences substantial gains in cognitive assessment scores, first-year students showed greater gains than returning students. Part of this difference was accounted for by returning students being older and entering with higher scores, but the remaining differences were not explained by family characteristics, classroom quality, or teacher characteristics. These findings may suggest that providing novel learning experiences to returning Head Start students might produce similar gains to those of first-year students.

Dr. Allison Friedman-Krauss of the National Institute of Early Education Research (NIEER), based at Rutgers University, shared research on the long-term effects of participating in one year of high-quality preschool vs. two years. Looking at middle- and high-school student outcomes, this research compared three cohorts of demographically similar children who had different preschool experiences: children who participated New Jersey’s Abbott Preschool program for one year, two years, or not at all. Children with one year of preschool performed better on a variety of outcomes than children who did not participate in the preschool program, and children with two years of preschool performed better still. The impact of Abbott Preschool participation on middle- and high-school outcomes is surprising in light of previous research on fade out indicating that the academic benefit of high-quality early childhood education may disappear as children continue their education. While the Abbott Preschool program shares important characteristics with the model preschool programs mentioned above, it is also relevant that participating districts offered universal access to the Abbott Preschool program as one element of broader reforms in preschool through third grade; students likely benefitted from the combination of reforms as they progressed through elementary school.

The transition from preschool to elementary school is a factor that may affect fade out: children who move from a high-quality learning environment in preschool to a lower-quality environment in elementary school may lose the advantages they gained in preschool. To ensure that its students could build on the benefits of high-quality pre-kindergarten when they transition to elementary school, Boston Public Schools (BPS) developed and implemented a curriculum that aligns instruction from pre-kindergarten through grade 2. At SRCD, Dr. Meghan McCormick of MDRC presented research on the association of instructional alignment in BPS with children’s literacy and math skills in kindergarten. Children who experienced pre-k and kindergarten classrooms that were both aligned to the city’s curriculum had statistically higher language and literacy scores than children whose classrooms were not aligned in one or both years. This exploratory study provides valuable evidence suggestive that instructional alignment across grades may impact child outcomes.

All three studies raise important questions for future research. The Head Start study examined children’s cognitive skills, but would the findings be different if we examined children’s social-emotional skills, which are a central focus of preschool programs? Could we determine whether the long-term achievement of Abbott Preschool students is the result of program participation or broader educational reforms? What would we learn if we expanded the Boston pre-k/kindergarten alignment study to include more children or more extensive measures of alignment?

These studies also offer important lessons for early childhood education and those who study it. Both New Jersey and Boston demonstrate useful models for providing high-quality preschool. Boston provides a model for supporting early learning across the kindergarten transition by aligning instruction, curriculum, and professional development from prekindergarten through grade 2. New Jersey’s Abbott Program demonstrates the promise of pairing high-quality universal preschool with broader reforms in preschool through grade 3. And all three studies demonstrate that the value of partnerships between researchers and education agencies: these studies’ rigorous approaches wouldn’t have been possible without the capacity provided by research organizations and the data provided by federal, state, or local partners. Researchers and practitioners can learn more in partnership than either could alone.

Submitted by Joanna Meyer on September 01, 2021