American Institutes for Research Issues a Policy Brief on Structuring Full-Day Kindergarten Programs to Maximize Reading Achievement

Washington, D.C. – The American Institutes for Research (AIR) has issued a policy brief summarizing the findings of its research on structuring instructional resources and practices for full-day kindergarten programs to increase children’s reading achievement and better prepare them for first grade. The brief notes, for example, that students in large classrooms show larger reading gains if they are divided into smaller groups based on their achievement levels.

The brief summarizes the findings in the AIR study, “Making the Most of Extra Time: Relationships Between Full-Day Kindergarten Instructional Environments and Reading Achievement,” which uses nationally representative data from the Early Childhood Longitudinal Study, Kindergarten Class of 1998-99 (ECLS-K), sponsored by the National Center for Education Statistics (NCES).

The policy brief examines the relationships between various approaches used in full-day kindergarten programs and reading gains experienced by children from the time they entered school to the end of the school year. The findings include:

  • Class size interacts significantly with some instructional practices to increase or decrease children’s average reading gains in kindergarten. The average full-day kindergarten class size was 21 children, with a range of between nine and 30 children. The study found that children in larger than average classrooms made larger reading gains when they spent more than one hour per week in small reading groups based on achievement level. Those gains diminished when they spent more time as members of a whole class for reading instruction.
  • Children in kindergarten programs that devote a larger portion of the school day to academic instruction, and to reading instruction in particular, show more improvement in reading than children who receive less instruction. Children spent about three-quarters of the instructional day on academic subjects (i.e., reading, mathematics, science, and social studies), with about half of academic time spent on reading. Children in programs that devoted a greater than average proportion of the day to academic subjects tended to make greater reading progress.
  • Children tend to make optimal gains in reading when teachers use an equal balance of specific literacy skills and comprehension skills instruction. The results suggest that increasing the amount of time spent on specific literacy skills – like reading aloud fluently and learning to spell – from an average of 1.9 days per week to 2.6 days per week, and decreasing the frequency of comprehension-based skills instruction from the average of 3.1 days per week to 2.5 days per week – improves reading gains.

Trained ECLS-K assessors used computer-assisted personal interviews to conduct one-on-one testing with children in reading, mathematics and general knowledge in the fall and spring of the kindergarten year. The reading score reflects children’s knowledge of basic skills (e.g., print familiarity, letter and word recognition), receptive vocabulary (e.g., recognition of written or spoken words), and comprehension. The reading gains were based on the difference between their fall and spring reading scores.

The full brief is available for download on the AIR website,

About AIR
Established in 1946, with headquarters in Washington, D.C., the American Institutes for Research (AIR) is a nonpartisan not-for-profit organization that conducts behavioral and social science research and delivers technical assistance both domestically and internationally in the areas of health, education and workforce productivity. For more information, visit


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