The study, out of Harvard University, appears in the journal Child Development. Some of the study's findings on the effects of the program are the largest found to date in evaluations of large-scale public prekindergarten programs.
Researchers found that the program substantially improved children's language, literacy, math, executive function (the ability to regulate, control, and manage one's thinking and actions), and emotional development skills citywide. Children in the program were 4 and 5 years old and from racially, linguistically, and socioeconomically diverse backgrounds. While all students who participated benefited, the improvements were especially strong for Latino children.
Preschool has been shown to help prepare children for kindergarten and is an increasing priority among federal, state, and local policymakers. But many preschool programs struggle to attain good instructional quality.
"We can draw several important lessons from our findings about factors that support quality in prekindergarten," notes Christina Weiland, incoming assistant professor at the University of Michigan's School of Education, who was at Harvard when she led the study.
First, the combination of explicit, evidence-based curricula (in language/literacy and math) and in-classroom coaching of teachers as part of professional development likely played a major role in improving student outcomes. Investing in such quality supports for prekindergarten teachers may lead to gains in students' school readiness, the study found.
Second, implementing consistent math, language, and literacy curricula might build children's executive function skills. "Our results suggest that curricula in these areas may also improve such domains as executive functioning, even without directly targeting them," according to Weiland. "Interestingly, research shows that these kinds of skills—which reflect early brain development, the ability to focus, and behavior—are critical to children's success down the road."
Third, students in the program also may have benefited from having more mixed-income peers than is typical in most public prekindergarten programs, which are means tested and therefore tend to include mostly low-income students.
"Given the particularly large impacts for Latinos, a group that tends to be underenrolled in preschool programs, efforts to increase the enrollment of Latino children in high-quality prekindergarten programs such as the one studied here may be beneficial," Weiland adds.