Delivering a landmark international study in early learning

As governments around the world continue to invest in early childhood education, there is growing recognition that understanding learning at this stage is essential. Strong evidence from the early years supports better decisions, earlier support and more equitable outcomes for children. 

The OECD International Early Learning and Child Well-being Study (IELS) represents a significant step forward in this effort. It is the first internationally comparative study designed to measure children’s learning and development at the age of five, at or just before they enter formal schooling. By focusing on this critical transition point, IELS strengthens understanding of how early learning systems are supporting children to arrive at school ready to learn and engage. 

A holistic view of early learning 

IELS examines children’s development across 10 key domains that underpin lifelong learning, including emergent literacy, emergent numeracy, executive function, and social and emotional skills. Together, these areas provide a holistic picture of how children learn, regulate their behaviour, engage with others and adapt as they transition into school. 

The study is built on a child‑centred assessment design that reflects how young children demonstrate learning. Using a direct assessment approach, children participate in short, story‑based or game-like activities delivered on a tablet, through visual and audio cues and administered one‑to‑one by trained assessors. The assessment does not require reading skills and is designed to be engaging, allowing children to show what they know and can do in authentic ways. 

Insights that strengthen early learning systems 

Early insights from IELS highlight important patterns in children’s development across participating jurisdictions. Across all domains, girls demonstrate stronger outcomes than boys at age five, including in the foundational learning areas of early literacy and numeracy and especially in social and emotional development. This illustrates how early developmental trajectories can differ and underscores the importance of supporting learning and wellbeing from the earliest years. 

The results also show that differences linked to socio‑economic circumstances are already visible before children begin school, particularly in foundational learning skills of literacy and numeracy. These early gaps highlight how access to early learning opportunities shapes children’s outcomes well before formal schooling begins. Understanding these patterns reinforces the importance of early, sustained investment in equity‑focused policies and supports. 

At the same time, differences associated with immigration background or home language are comparatively small and often diminish once broader socio‑economic circumstances are taken into account. 

IELS also points to the critical role of children’s everyday learning environments. Rich home learning environments and active family engagement with early learning settings are consistently associated with stronger learning and wellbeing outcomes across domains. These findings emphasise the value of strong partnerships between families and early childhood education and care (ECEC) services. 

While earlier and more intensive participation in ECEC programs is associated with stronger early literacy and numeracy outcomes, the study shows that participation alone is not sufficient to ensure equitable outcomes. This points to the need for sustained attention to access to high quality ECEC programs and meaningful engagement with families to ensure early learning systems support all children to thrive. 

More broadly, the study demonstrates the value of measuring a wide range of skills at this stage of development. By looking beyond narrow academic outcomes, IELS helps build a richer understanding of the capabilities that support learning, wellbeing and engagement as children move into school. 

ACER’s role in delivering IELS 

IELS was delivered by an international consortium under OECD leadership, with ACER serving as lead contractor. In this role, ACER coordinated delivery across participating jurisdictions and led the development of the assessment framework, instruments and delivery platform and undertook the psychometric modelling that underpin the study. 

ACER also managed the delivery of a substantial body of supporting work, including translated and adapted item pools, databases, technical reports and operational manuals that supported multi‑year field trials and main study implementation. These artefacts were critical to ensuring consistency, quality and comparability across diverse cultural and linguistic contexts. 

This work reflects ACER’s strengths in psychometrics, educational research and large‑scale project delivery, as well as its capability to deliver technically rigorous international studies at scale under OECD leadership. It builds on ACER’s involvement in the inaugural cycle of IELS in 2018 and contributes directly to its broader expertise in early childhood assessment and research. 

Strengthening the evidence base for early learning 

Through IELS, ACER has supported the development of a globally significant source of evidence on early learning and well-being. By strengthening understanding of how early childhood systems support children in the years before school, the study contributes to international efforts to improve learning outcomes and promote equity from the very start of education.

Read the OECD International Early Learning and Child Well-being Study.