This chapter outlines key elements of the design and implementation of the second cycle of the International Early Learning and Child Well-being Study (IELS 2025). This includes its objectives and guiding principles, the target group of children sampled, the aspects of early learning and development that were assessed, the variety of assessments carried out, and the contextual information gathered about children from parents and teachers. The chapter concludes by highlighting avenues for future developments.
Building Strong Foundations for Life
Results from the 2025 Early Learning and Child Well-being Study
Abstract
The OECD’s International Early Learning and Child Well-being Study (IELS) was developed to support countries and jurisdictions in their efforts to improve children’s learning, development and well-being in the early years. The study collects a broad range of information on the drivers, levels and gaps in children’s early learning and development outcomes, and provides participant jurisdictions with reliable, valid and comparable data to monitor the extent to which their early years policies give all children a strong start in life.
Nine jurisdictions participated in the second cycle of the study (hereafter, IELS 2025), including four countries – Korea, Malta, the Netherlands and the United Arab Emirates – and five sub-national entities – Baku and Sumgait (Azerbaijan), Ceará, Pará and São Paulo (Brazil), England (United Kingdom), the Flemish Community (Belgium), and Hangzhou (China)1. Additionally, Abu Dhabi participated as an adjudicated region within the United Arab Emirates (see the IELS 2025 Technical Report (OECD, 2026[1]).
The data collection for the main study was completed in 2025, building on field trials implemented in 20242 and the foundational work of the first cycle, which was completed in 2020 with the participation of England (United Kingdom), Estonia, and the United States. The consolidation of IELS and its assessment framework across two cycles lays the groundwork for bringing a comparative perspective to the study of trends in children’s early learning and development outcomes.
Objectives and guiding principles
A fundamental objective of IELS is to provide evidence to help jurisdictions identify where improvements can be made to enhance children’s early years experiences and outcomes. International comparative data help policy makers, education leaders and early childhood practitioners understand what is possible to achieve for children in the early years3. This includes key system goals such as mitigating disadvantage and ensuring that children are well-positioned to succeed in school.
To achieve this objective, IELS contributes to the evidence base by providing a population-level assessment that reflects how a cohort of children is doing. This enables jurisdictions to observe differences in outcomes across various groups of children, including girls and boys, socio-economic groups, and children from migrant or linguistically diverse backgrounds. While the analysis in this report remains largely descriptive, connections between findings from the study and the policy context in each jurisdiction can support inferences that inform policy prioritisation, shape recommendations, guide further research questions, or support evaluations of previously enacted policy interventions.
The first cycle of IELS was developed in conjunction with countries interested in children’s early learning, development and well-being. As well as setting the objectives for the study, participants agreed on a set of guiding principles to steer its design, development and implementation, newly summarised below for this second cycle:
Policy relevance: Capacity to inform changes in policy and/or practices.
Reliable, valid and comparable: across jurisdictions, languages, cultural contexts and over time.
Ethical: ensuring the well-being of participant children in all decisions.
Practicable, efficient and cost-effective: a study that can be implemented without undue effort and cost burdens on jurisdictions, practitioners, parents and children.
The conceptual design of the study
IELS study focuses on a number of dimensions of children’s early learning and development that have been found to be strong and consistent predictors of positive later outcomes, including educational achievement and attainment, mental and physical health, employment and earnings, citizenship, wider well-being and life satisfaction (see Chapter 1 and the IELS 2025 Technical Report (OECD, 2026[1])).
The IELS assessment is intended for population-level monitoring and reporting and should be interpreted as an aggregate picture that illustrates how a cohort of children is faring overall. It should not be used to make judgements about any single child’s strengths and weaknesses or to evaluate individualised support needs. By assessing multiple domains of early learning and development, the study can provide insights into the strength of inter-relationships among these different domains and the extent to which different groups of children experience such overlapping skill sets. Children who are developing well in one area may be developing equally well in others, but disparities in the pace of skill development may also exist between areas. These insights can inform the design of policies and specific interventions to support children in developing a balanced set of early skills that become a strong foundation for further growth and well-being.
The study also captures relevant contextual information relating to children’s individual characteristics, families and home environments, and experiences in early childhood education and care (ECEC) and the initial years of primary schooling. This information is essential in answering policy and research questions about factors associated with stronger and weaker outcomes in these key domains, and for identifying gaps between different groups of children.
The target group of children sampled in the study
The children in the study are five-year-olds enrolled in regulated ECEC centres or schools in their respective jurisdictions. Age 5 is often the point at which children are about to enter or have just entered the schooling system, and it is also the point at which OECD countries reach near-universal participation in some form of formal early education. While some jurisdictions have not yet achieved universal participation by age 5, most are progressing toward universality at this stage, driven by growing enrolment rates in ECEC and earlier entry into schooling.
IELS carries out its assessments at a common age, rather than at a particular stage of education, in order to provide a more comparable basis across jurisdictions. A stage of education refers to a level or step within an education system, such as the point of entry to school or the last year of ECEC. The names and features of the educational settings where five-year-olds are enrolled typically vary across jurisdictions (see Chapter 6). Selecting an age rather than a specific stage or grade enables jurisdictions to understand what children of the same age in other jurisdictions know and are able to do, inviting reflection on the structure of ECEC and early schooling systems, regarding for instance features such as starting ages, duration, and curriculum.
Children in IELS are assessed in the ECEC centre or school they attended at age 5, to ensure the assessment was carried out in a setting the child was familiar with, as well as for reasons of practicality and cost. Accessing children in formal educational settings is generally easier and less costly than locating them and conducting assessments in their home or other settings.
To achieve jurisdiction-level representative samples, IELS uses a two-stage probability design. In the first stage, a random sample of ECEC centres/schools was selected in each jurisdiction. In the second stage, a random sample of children was selected from the list of eligible children within each selected ECEC centre/school. Overall, more than 23 000 children took part in the IELS 2025 main study across the nine participant jurisdictions. Statistical weightings are applied to enable accurate inferences about the jurisdiction-level population (see IELS 2025 Technical Report (OECD, 2026[1])).
The aspects of children’s early learning and development that are assessed
All aspects of children’s early learning and development matter for their well-being and ongoing success in childhood and in adulthood. However, there is also a significant degree of overlap across aspects and measuring every distinct dimension of early and development to gauge how well children are faring is neither necessary nor feasible. In selecting a meaningful and manageable set of early skills for the study, IELS applied the following criteria:
Broad rather than narrow, i.e. covering sufficient dimensions to provide an accurate indication of children’s early development and likely later outcomes.
Predictive of children’s later trajectories, across a broad set of positive outcomes in adulthood, beyond an exclusive focus on educational achievement.
Related to the learning that develops in early childhood and that can be developed through early years programmes, including in ECEC/school settings.
Manageable in the time required from children, parents and teachers to participate in the study, and in terms of the cost of developing and implementing the study.
Based on these considerations, IELS 2025 measures a balanced set of skills across three dimensions of children’s early learning and development: foundational learning, executive function and social and emotional development (see the IELS 2025 Assessment Framework (OECD, 2026[2]). Figure 2.1 list these dimensions and the domains included in each of them, as well as the mode of assessment.
In IELS 2025, three sources of information provide a many-sided perspective on children’s early learning and development:
A direct assessment of each child in seven domains (i.e. the two foundational learning domains of emergent literacy and emergent numeracy; the three executive function domains of inhibition, working memory and mental flexibility; and the social and emotional development domains of emotion identification and emotional attribution).
A questionnaire completed by each child’s ECEC/school teacher, including:
an indirect assessment of each child in three domains (e.g. the social and emotional development domains of trust, pro-social behaviour and non-disruptive behaviour);
perceptions about each child’s cognitive and motor skills, social and emotional skills, and global capabilities.
A questionnaire completed by each child’s parents/guardians, including:
perceptions about each child’s cognitive and motor skills, and social and emotional skills.
In this way, the study triangulates information from direct assessment of the child with indirect assessments of the child provided by adults who knew them well. This approach enables IELS to assess children’s early learning and development across a broader scope of domains than is possible through a direct assessment alone. For details on the construction of scores in the three indirectly assessment domains and the teacher’s and parent’s perceptions indices, see the IELS 2025 Technical Report (OECD, 2026[1]).
Note: Domains in dark blue font are directly assessed through play-based assessment on tablets, with one-to-one support from a trained study administrator. Domains in light blue font are indirectly assessed through reports from ECEC/school teachers. Emergent literacy includes three sub-domains: listening comprehension, vocabulary and phonological awareness. Emergent numeracy includes five sub-domains: numbers and counting, working with numbers, measurement, shape and space, and pattern.
Source: IELS 2025 Assessment Framework (OECD, 2026[2]).
Foundational learning
Foundational learning encompasses what are traditionally understood of as the skills children learn in early education settings. In IELS, two specific domains are assessed in this dimension: emergent literacy and emergent numeracy. These are fundamental skills that enable children to have a strong start in later stages of education where they will learn reading, writing and mathematics. Importantly, these emergent skills are precursors to later learning.
Emergent literacy is a child’s capacity to use knowledge and skills to understand information and narratives, as a developmental precursor to reading and writing (Whitehurst and Lonigan, 1998[3]) (Horowitz‐Kraus and Hutton, 2015[4]). In IELS, the emergent literacy assessment included three sub-domains: listening comprehension, vocabulary and phonological awareness. Listening comprehension incorporates a range of early literacy skills, such as understanding the explicit and implied meaning of spoken language, including standalone sentences. Vocabulary knowledge is fundamental to comprehension and to successful communication with others, thereby further developing emergent literacy as well as social connectedness. Phonological awareness is the ability to detect, manipulate and analyse the auditory aspects of spoken language.
As an innovation in IELS 2025 a multi-stage adaptive design was used for the assessment of emergent literacy, which presented children with questions appropriately challenging for their ability level and to support appropriate targeting to a range of proficiency levels. A branching design was used for the literacy sub-domains of listening comprehension and vocabulary, while a stop rule was introduced for the sub-domain of phonological awareness.
Emergent numeracy refers to the range of informal number and quantity skills that children in their early years, and which involve the understanding and manipulation of both symbolic and non-symbolic number (Bisanz et al., 2005[5]) (Raghubar and Barnes, 2016[6]). In IELS, emergent numeracy is defined as children’s early mathematical thinking, including their ability to mathematise through reasoning and problem solving as relates to real-world contexts. Emergent numeracy skills that predict later positive outcomes for children are as much about the processes of mathematics as about content. Through early stages of development, children learn that things can be measured, such as by counting objects and comparing lengths and weights. At age 5, children also develop organised ways of thinking about and addressing mathematical problems to arrive at solutions.
In IELS 2025, the emergent numeracy assessment covered five sub-domains: numbers and counting, working with numbers, measurement, shape and space, and pattern. In the sub-domain of numbers and counting, children are for instance asked to identify digits and numbers up to 20. In the sub-domain of working with numbers, sample tasks included adding and subtracting in informal number story contexts. The measurement sub-domain focuses on the ability to use everyday language compare measures (e.g. longer, heavier). Shape and space assessed children’s understanding of common shapes (e.g. identify triangles) and use of language of location (e.g. above). In turn, the pattern sub-domain is concerned with children’s ability to recognise and create patterns of shapes or objects.
Executive function
Executive function is the cognitive aspect of self-regulation4, which is a complex construct that supports purposeful, goal-directed, problem-solving behaviour (Diamond, 2013[7]) (Hofmann, Schmeichel and Baddeley, 2012[8]) (Diamond, 2013[7]) (Hofmann, Schmeichel and Baddeley, 2012[8]) (Bailey, 2018[9]). IELS focuses on three core components of executive function: inhibition, working memory, and mental flexibility.
The domain of inhibition relates to children’s ability to regulate impulsive and automatic reactions and switch attention or consciously choose and concentrate on the required tasks.
Working memory reflects a child’s ability to store information for current use and bring it to bear to complete tasks. Children with well-developed working memory are typically able to follow instructions without the need for frequent repetition. Mental flexibility refers to children’s ability react quickly to changing stimuli or shifts in rules or circumstances, helping them to manage complex and multiple tasks. In the IELS 2025 assessment, each of these domains was presented as a series of games and is divided into clusters of items of increasing difficulty, with the next cluster only being accessible if the child is managing above a designated level.
Social and emotional development
Social and emotional are individual capacities that enable people to collaborate with others, as well as regulate one’s own emotions and behaviour to achieve goals (Chernyshenko, Kankaraš and Drasgow, 2018[10]). During the early years, children form close relationships and develop expectations of behaviours for both them and others. They learn to regulate their emotions and actions, to take others’ perspectives and to empathise. These skills serve as the building blocks for later development of more complex social and emotional skills (Halle and Darling-Churchill, 2016[11]) (Campbell et al., 2016[12]). IELS 2025 measures five domains of children’s social and emotional development: emotion identification and emotional attribution (together conceptualised as empathy), trust, pro-social behaviour, and non-disruptive behaviour.
In IELS, empathy refers to the ability of children to understand and respond to the thoughts, intentions and emotional states of others. The study uses empathy tasks that contrast the emotional states of characters and particular social situations in stories. It measures two components of empathy. The first component is emotion identification, which relates to ability to identify the emotions of others. The second component is emotional attribution, which pertains to the correspondence between the child’s emotional response to a story and the emotions experienced by the characters in the story.
In IELS, the domain of trust relates to social confidence or the child’s capacity to establish interpersonal trusting relationships. The domains of pro-social behaviour and non-disruptive behaviour concern social behaviours that might be expected to be influenced by children’s experiences in ECEC centres/schools, and are based on a modified version of the Adaptive Social Behaviour Inventory (ASBI), an instrument developed as a general measure of social competence for pre-school-aged children (Hogan, Scott and Bauer, 1992[13]). Positive dimensions related to expression and compliance were combined into a measure of pro-social behaviour. Disruptive aspects were used to infer the inverse, that is, the child’s non-disruptive behaviour.
IELS 2025 uses both direct and indirect assessments of children’s social and emotional development skills: empathy-related domains are assessed directly, whereas trust, pro-social behaviour and non-disruptive behaviour are measured indirectly through reports from ECEC/school teachers5. More information on the indirectly assessed domains is provided below.
How children are assessed
Direct assessment
Children completed a direct, play-based assessment on tablets, with one-to-one support from a trained study administrator. The children listened to stories and interacted with cartoon-like characters by touching or moving items on the screen. The assessment uses drag-and-drop technology, where children move items on the screen, as well as hot-spot technology, where children tap objects to show their preferred choice. Study administrators ensured each activity was ready before children started and that each child could navigate his or her way through the activities. The study administrator remained with the child throughout the assessment sessions.
Each direct assessment activity took approximately 15 minutes. Two assessment activities were administered per day, across two days. The two-day format aimed to ensure that children were neither overburdened by the assessment nor removed from the regular environment of their ECEC centre/school for an extended period of time.
The stories and other activities the children engaged in during the assessment were designed to be interesting, fun and developmentally appropriate for this age group. Two child characters (shown in Figure 2.2) guided the children through the activities via audio. The names and physical characteristics of these lead characters were adapted to the context of each participating jurisdiction. No reading or writing was involved in the direct assessment activities; only visual and auditory materials were used.
Indirect assessment through the ECEC/school teacher questionnaire
The questionnaire completed by the teacher or staff member who knew each child best in their ECEC centre/school included several questions about the child’s learning and development, as reflected in behaviours that teachers observed at the ECEC centre/school the child attends.
Teachers were asked to select the response that best described the child on a series of 28 statements relating to children’s behaviours and attitudes when interacting with other children and with adults6. Responses to this question were used to estimate children’s scores on three indirectly assessed social and emotional development domains of trust, pro-social behaviour and non-disruptive behaviour Examples of the items in the question include: “Greets unfamiliar children in a friendly way” (trust); “Tries to comfort others when they are upset” (pro-social behaviour); and ”Prevents other children from doing their own activities” (non-disruptive behaviour).
Teachers were also asked about the child’s ability to complete a series of tasks7 involving emergent literacy or emergent numeracy (e.g. “sort a group of objects by shape, size or colours”; “count in multiples”; “recognise the sounds of words that rhyme”), as well as related to empathy (e.g. “draw inferences about how a character felt after listening to a story”). Techers’ perceptions were used to estimate the child’s values on the index of ‘global capabilities’.
Source: IELS 2025 Assessment Framework (OECD, 2026[2]).
Lastly, teachers were asked to rate the level of development of the child relative to typical development on 12 different areas8, pertaining for instance to expressive language skills (e.g. “understands, interprets, listen”), fine and gross motor skills (“catches and throws balls”, “plays with small objects likes beads or bricks”), mood and emotion control (“gets over being upset quickly”) or peer relationships (“plays easily with others”). Teachers’ perceptions were used to estimate the child’s values on the teacher indices of ‘cognitive and motor skills’ and ‘socio-emotional skills’.
Indirect assessment through the Parent questionnaire
The Parent questionnaire included also some questions about the child’s learning and development, as reflected in behaviours that parents/guardians observed at home. Parents/guardians were asked to rate the level of development of the child relative to what they would estimate as typical development on 12 different areas9, using the same question as teachers. Parents’ perceptions were used to estimate the child’s values on the parent indices of ‘cognitive and motor skills’ and ‘socio-emotional skills’.
Contextual information on each child
Contextual information on children’s individual characteristics, family context and home environments and experiences in ECEC/school is essential for understanding how these factors interact with their early learning and development outcomes. IELS 2025 administered contextual questionnaires to both parents/guardians and ECEC/school teachers to collect such information. Questionnaires were primarily delivered online, with a paper-based version available for participants without internet access. For details on the design of the contextual questionnaires and their alignment with the conceptual framework of IELS, see the IELS 2025 Technical Report (OECD, 2026[1]); for details on response rates and mode of administration, see the Reader’s Guide.
Individual characteristics of children
Information on the individual characteristics of each child participating in the study was collected from parents/guardians. This included:
Exact age, transformed into age in months for analysis in this report.
Gender.
Whether the child experienced any developmental challenges, including a low birthweight, a premature birth, or sensory, learning or behavioural difficulties.
Family context and home environments
Information on aspects of home environments with the potential to influence children’s early learning, development and well-being was collected from parents/guardians. This included:
Household composition, such as whether the child lived in a one- or two-parent household, the number of siblings of the child, and the age of parents/guardians.
Socio-economic status of the family, including parents/guardians’ employment status and occupations, highest levels of education completed, and annual household income. Consistent with other large-scale assessments, IELS uses this information to construct an index of socio-economic status; for details, see the Reader’s Guide and the IELS 2025 Technical Report (OECD, 2026[1]).
Immigration background of the parents/guardians and the child.
Language(s) spoken at home by the parents/guardians and the child.
Number of children’s books in the home, and the frequency of use of digital devices by the child.
Frequency of parent-child activities with a learning and developmental focus, such as reading with the child and engaging in back-and-forth conversations.
ECEC/school participation and additional supports
Information on the child’s enrolment in ECEC or the early years of schooling up to age 5 was collected from parents/guardians. This included:
Whether the child regularly attended an ECEC centre/school between ages 0 to 5.
The types of ECEC or school attended by the child at each specific age, with questions adapted according to the organisation of the early education system of each jurisdiction.
The number of hours that the child attended those settings.
Further, ECEC/school teachers provided information on whether the child had received different types of additional support services, such as learning or behavioural support, or support with the language of assessment.
IELS provide evidence that helps jurisdictions see where they can improve children’s early learning and development outcomes. Cross-jurisdictional comparative data can help policymakers, researchers and professionals in early education and care to address key issues in early childhood policy and practice, including reducing inequalities and helping all children start school ready to thrive. With the aim of strengthening the policy relevance of the analysis of IELS 2025 data, subsequent chapters in this report are structured around key questions:
Chapter 3: How five-year-olds are faring: What are average scores and variation in children’s early learning and development outcomes across the jurisdictions participating in IELS 2025? What are the associations between average scores and jurisdictions’ contextual factors? How do children’s scores and parents’ and teachers’ perceptions of their skills correlate with each other? How do children’s outcomes across domains of assessment correlate with each other?
Chapter 4: Equity gaps in early learning and development: How are children’s early learning and development outcomes associated with their gender, socio-economic, immigration and language backgrounds? Are the gaps in assessed outcomes consistent with parents’ and teachers’ perspectives on children’s skills?
Chapter 5: Home environments and early learning and development: How are children’s early learning and development outcomes associated with home environments? What are the associations with factors such as parental levels of education, household structure, parent-child activities, or parents’ engagement in the child’s ECEC centre/school?
Chapter 6: Early childhood education and care, additional supports, and early learning and development: What are the ECEC/school participation patterns among children in IELS 2025? How is participation in ECEC/school associated with children’s early learning and development outcomes by age 5? What proportions of children in IELS 2025 experience early difficulties and receive special supports? How are these special supports associated with children’s early learning and development outcomes?
Avenues for future developments
The topics examined in this report represent a small sample of the broad range of research and policy questions that IELS 2025 can inform. Alongside this report, the OECD has released Public Use Files (PUF) intended not only to enable the replication of the OECD’s analysis, but also to facilitate further secondary analysis by researchers. In addition to open-access datasets, the International Database Analyzer (IDB Analyzer) software tool of the International Association for the Evaluation of Educational Achievement (IEA) is freely available to download. There are numerous open questions that the high-quality IELS datasets could help explore, particularly when analyses are conducted in line with the study design. An expanded range of participant jurisdictions in future cycles of the study would increase the potential scope for both comparative and jurisdiction-specific analysis. In the same vein, trend analysis could be conducted for jurisdictions participating in several cycles of IELS.
Importantly, IELS data could be analysed in connection with data from other studies. For instance, other OECD large-scale assessment programmes measure related skills at different stages of the life course. The Programme for International Student Assessment (PISA) assesses reading and mathematics, the Survey of Adult Skills (PIAAC) assesses literacy and numeracy, and the Survey on Social and Emotional Skills (SSES) assesses social and emotional skills. This creates opportunities to use IELS, PISA, SSES and PIAAC – which assess individuals in early childhood, adolescence, and adulthood, respectively – together to examine long-term learning trajectories. However, many challenges exist to making direct and valid comparisons based on different surveys, including differences in their target populations, test administration procedures and assessment frameworks.
Going forward, an improved alignment between the conceptual and assessment frameworks of IELS and those of other OECD surveys, including PISA, PIAAC or SSES could create new opportunities to combine data across surveys to analyse skills development and equity outcomes from a longitudinal perspective, such as through birth cohort comparisons. This would require theoretical and methodological groundwork to explore whether different assessments can be positioned along a developmental continuum and to better understand what learning progressions look like over time.
Meanwhile, connections with the Starting Strong Teaching and Learning International Survey (TALIS Starting Strong) could also bring enhanced opportunities to understand the role that ECEC and early schooling can play in promoting children’s early learning and development and in reducing inequalities in children’s outcomes.
References
[9] Bailey, R. (2018), Executive Function Mapping Project Measures Compendium: A Resource for Selecting Measures Related to Executive Function and Other Regulation-related Skills in Early Childhood., Office of Planning, Research and Evaluation, Administration for Children and Families, U.S. Department of Health and Human Services, https://acf.gov/opre/report/executive-function-mapping-project-measures-compendium-resource-selecting-measures (accessed on 16 January 2026).
[5] Bisanz, J. et al. (2005), Development of arithmetic skills and knowledge in preschool children. In Campbell, J. (Ed.) Handbook of mathematical cognition, Psychology Press.
[12] Campbell, S. et al. (2016), “Commentary on the review of measures of early childhood social and emotional development: Conceptualization, critique, and recommendations”, Journal of Applied Developmental Psychology, Vol. 45, pp. 19-41, https://doi.org/10.1016/j.appdev.2016.01.008.
[10] Chernyshenko, O., M. Kankaraš and F. Drasgow (2018), “Social and emotional skills for student success and well-being: Conceptual framework for the OECD study on social and emotional skills”, OECD Education Working Papers, No. 173, OECD Publishing, Paris, https://doi.org/10.1787/db1d8e59-en.
[7] Diamond, A. (2013), “Executive Functions”, Annual Review of Psychology, Vol. 64/1, pp. 135-168, https://doi.org/10.1146/annurev-psych-113011-143750.
[11] Halle, T. and K. Darling-Churchill (2016), “Review of measures of social and emotional development”, Journal of Applied Developmental Psychology, Vol. 45, pp. 8-18, https://doi.org/10.1016/j.appdev.2016.02.003.
[8] Hofmann, W., B. Schmeichel and A. Baddeley (2012), “Executive functions and self-regulation”, Trends in Cognitive Sciences, Vol. 16/3, pp. 174-180, https://doi.org/10.1016/j.tics.2012.01.006.
[13] Hogan, A., K. Scott and C. Bauer (1992), “The Adaptive Social Behavior Inventory (ASBI): A New Assessment of Social Competence in High-Risk Three-Year-Olds”, Journal of Psychoeducational Assessment, Vol. 10/3, pp. 230-239, https://doi.org/10.1177/073428299201000303.
[4] Horowitz‐Kraus, T. and J. Hutton (2015), “From emergent literacy to reading: how learning to read changes a child’s brain”, Acta Paediatrica, Vol. 104/7, pp. 648-656, https://doi.org/10.1111/apa.13018.
[2] OECD (2026), IELS 2025 Assessment Framework, http://oecd.org/en/about/projects/international-early-learning-and-child-well-being-study.
[1] OECD (2026), IELS 2025 Technical Report, http://oecd.org/en/about/projects/international-early-learning-and-child-well-being-study.
[6] Raghubar, K. and M. Barnes (2016), “Early numeracy skills in preschool-aged children: a review of neurocognitive findings and implications for assessment and intervention”, The Clinical Neuropsychologist, Vol. 31/2, pp. 329-351, https://doi.org/10.1080/13854046.2016.1259387.
[3] Whitehurst, G. and C. Lonigan (1998), “Child Development and Emergent Literacy”, Child Development, Vol. 69/3, pp. 848-872, https://doi.org/10.1111/j.1467-8624.1998.tb06247.x.
← 1. Results from Hangzhou (China) are not included in this report. See Reader’s Guide for more information.
← 2. Korea and Hangzhou (China) implemented only an operational field trial in early 2025.
← 3. International comparisons should be made with caution given contextual differences between jurisdictions, particularly when the level of participation (i.e. national, regional, municipal) differs.
← 4. In the first cycle, this dimension was labelled ‘Self-regulation’. Following recommendations by the IELS Technical Expert Group, the labelling in the second cycle changed to ‘Executive function’. Self-regulation is a broader concept that includes both cognitive and emotional types of self-regulation. The IELS assessment captures mainly the cognitive aspects of self-regulation, which are commonly referred to as executive function or cognitive control.
← 5. Since the first cycle of IELS revealed that parents tended to use a limited (and generally positive) range of response categories, and to shorten the Parent Questionnaire, the second cycle of IELS collected trust, pro-social behaviour and non-disruptive behaviour data exclusively from children’s teachers.
← 6. This is Question 6 of Section B of the International version of the Staff questionnaire. Teachers responded to the 28 items/statements using a 5-point Likert scale for frequency ranging from “Never” to “Always”.
← 7. This is Question 4 of Section B of the International version of the Staff questionnaire. Response options to the 9 items/statements were “Yes”, “No” and “Not sure”.
← 8. This is Question 5 of Section B of the International version of the Staff questionnaire. Teachers responded to the 12 items/statements using a 5-point Likert scale ranging from “Much less than average” to “Much more than average”.
← 9. This is Question 5 of section A of the International version of the Parent questionnaire. Parents responded to the 12 items/statements using a 5-point Likert scale ranging from “Much less than average” to “Much more than average”.