As every parent knows, preschool must all too often be purchased at a hefty price. In addition to the hot debate over whether preschool itself is really all that important, a new study sparks a fresh debate on whether part-day or full-day programs are best suited to prepare a child for school.

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Along with aiding children’s social development, preschool has been found to instill academic benefits beyond initial years of school.

The debate over the benefits of preschool has been launched into the national spotlight ever since President Obama called for universal access to high-quality preschool education for every American 4-year-old in his 2013 State of the Union address.

There is a growing body of academic research about the benefits of pre-K education, including a consensus among researchers that children who receive it perform better academically in kindergarten. Preschool has also been found to aid in children’s social development. Many studies have shown that the social and academic benefits persist beyond the initial years of school.

Although publicly funded preschool programs, such as Head Start and state pre-kindergarten, serve an estimated 42% of 4-year-olds in the US, most provide only part-day services, and only 15% of 3-year-olds enroll.

These rates, plus variations in quality, may account for only half of children entering kindergarten having mastered the skills needed for school success.

Arthur J. Reynolds, PhD, of the University of Minnesota, Minneapolis, and colleagues hypothesized that one approach for enhancing effectiveness of preschool programs may be to increase attendance from a part-day to a full-day schedule.

The researchers investigated whether full-day preschool was associated with higher levels of school readiness, attendance and parent involvement, compared with part-day participation.

The study, published in in the November 26th issue of JAMA, compares 982 predominantly low-income, ethnic minority children aged 3 and 4 in 11 Chicago Child-Parent Centers (CPC) that run both full-day (7 hours) and part-day (3 hours) programs.

Children were not randomly selected for full- or part-day programs, due to the high likelihood of non-adherence by parents and school resistance. The project team used three criteria to assign children to the full-day program:

  1. Children aged 4 years rather than 3 years
  2. Parental preference due to employment, education or transport barriers
  3. Lack of available care for the other part of the day.

Children in both groups attended preschool 5 days a week for at least 3 months and began no later than January 2013.

At the end of preschool, the researchers evaluated:

  • School readiness skills (in several subcategories) of the children
  • Attendance and chronic absences
  • Parental involvement.

Among the 11 centers, 409 children enrolled in full-day classes and 573 in part-day classes.

School readiness

Full-day participants demonstrated higher scores than part-day participants in six subcategories:

  1. Language: 39.9 versus 37.3
  2. Math: 40.0 versus 36.4
  3. Socio-emotional development: 58.6 versus 54.5
  4. Physical health 35.5 versus 33.6
  5. Literacy: 64.5 versus 58.6
  6. Cognitive development: 59.7 versus 57.7.

In the full-day group, 80.9% were at or above the national average on 4 or more subcategories, compared with 58.7% of the part-day group. Full-day preschool was associated with around a third of a year (3-4 months) improvement in all categories except cognitive development (1-1.5 months).


Full-day participation was associated with a higher rate of average daily attendance and lower rates of chronic absences, compared with part-day participation:

  • Full-day attendance: 85.9%
  • Part-day attendance: 80.4%

Parental involvement

No significant differences were detected between the two groups for teacher and parent ratings of school involvement.

Children who attended the full-day preschool program had higher scores on measures of school readiness skills, increased attendance and reduced chronic absences, compared with children who attended part-day preschool.

Reynolds says:

Full-day preschool appears to be a promising strategy for school readiness. The positive association of full-day preschool also suggests that increasing access to early childhood programs should consider the optimal dosage of services.”

“In addition to increased educational enrichment, full-day preschool benefits parents by providing children with a continually enriched environment throughout the day, thereby freeing parental time to pursue career and educational opportunities. By offering another service option, full-day preschool can also increase access for families who may not otherwise enroll,” he concludes.

In an accompanying editorial, Lawrence J. Schweinhart, PhD, of the HighScope Educational Research Foundation, Ann Arbor, MI, comments that although the associations found in this study were statistically significant, “they may not be substantial enough to justify the larger expense of full-day preschool, essentially twice that of part-day preschool.”

“This must be debated and discussed by parents, educators, and policy makers and the longer-term effects and economic returns studied. In part, the importance of the study by Reynolds and colleagues is that it represents a contemporary sample of children and their families.” Schweinhart continues:

The study by Reynolds and colleagues provides evidence that high-quality, full-day programs are educationally more valuable than part-day programs.”

The 2012-2013 school year saw a loss of 9,160 children aged 4 from enrollment to state pre-K programs across 40 states. With this in mind, how many parents will view this new research as a positive indicator to enroll their child to a preschool program or switch from a part-day to a full-day schedule?