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Is Child Development Helped by an Extra Year of Preschool?

April 17, 2017

Growing evidence shows that preschool attendance increases young children’s readiness for school by improving cognitive and social-emotional development and this can have lasting benefits beyond primary, especially for socially and economically disadvantaged students. However, there is less evidence on how many years of preschool are needed for the most cost-effective impact. The study in Bangladesh will measure the impact of starting preschool a year earlier, at age four rather than age five, giving children two years of preschool instead of one. The Government of Bangladesh has emphasized preprimary education as part of the development of children and currently offers one-year preprimary education to five-year old children. The results will help Bangladesh decide whether to move forward with recommendations in the national education and early childhood policy programs to increase preschool to two years. 

Research area: Education

Country: Bangladesh

Evaluation Sample: schools 

Timeline: 2016 - 2019

Intervention: preschool 

Researchers: Johannes M. Bos, American Institutes for Research; Najmul Hossain, Data International; Marianne O’Grady, Save the Children; Josh Sennett; Kaitlin Carson; Shinsaku Nomura, World Bank Task Team Leader (TTL)


Save the Children has been running a one-year preschool program in 25 centers in Bangladesh’s Meherpur district since the end of 2014. With the expansion of the program in 2016 to an additional 50 new centers, an opportunity was created to include a randomized control trial to measure the benefits of a pilot program adding an extra year of preschool.


The classes for four year olds will use the existing preprimary infrastructure and resources of the preschool program for five year olds, but with different curriculum and materials. The classes usually are staggered to allow use of the same centers – while government preprimary classes are in the morning, the early years’ program general run in the afternoon.


The evaluation is a cluster randomized controlled trial that randomly assigns 100 preprimary centers to be either in the treatment or control groups. The evaluation is taking place in the rural parts of the district of Meherpur.

The evaluation will estimate the effect of receiving two years of preschool education through the Save the Children early years’ program for four-year-olds and the government preprimary program for five-year-olds, versus the effect of receiving one year of preschool education through the government preprimary program.

The target population for the impact evaluation are children aged three years and older who in 2018 will be five years old and eligible to enroll in the government preschool program. 

Study questions

What is the impact of offering an additional year of preschool on the cognitive development of young children in a rural setting? What is the impact of offering an additional year of preschool on the social-emotional abilities and motor development of young children in a rural setting? What is the benefit relative to the cost of offering an additional year of preschool with regard to learning and development outcomes?

Data Collection

The team will collect early childhood development measures using the International Development and Early Learning Assessment tool (IDELA) developed by Save the Children. IDELA is an easy-to-use, direct assessment prototype that measures early learning and development of children between 3.5 and 6.5 years of age. IDELA, which provides a holistic picture of children’s development and learning, covers four developmental domains: Emergent literacy and language, emergent math, social-emotional development, and motor development skills. Regarding emergent literacy and language, the tool measures factors such as print concepts, alphabet knowledge, expressive and receptive language, phonemic awareness, listening comprehension, and emergent writing. Regarding emergent math, the tool measures aspects such as counting; number and quantity identification; concepts of time, direction, space, and shapes; and sorting, patterns, and problem solving. The social-emotional development domain includes reacting to situations involving emotions, perspective taking, conflict resolution, and compassion. Finally, the motor development domains capture gross and fine motor abilities, among others.  

The child development outcomes will be collected in three rounds: At the beginning of 2017, at the beginning of 2018, and at the end of 2018. In each round the team expects to collect data from approximately 1200 children.