The International Early Learning and Child Well‑being Study (IELS) is a collaborative effort that brings together the expertise of participating countries and jurisdictions committed to improving the evidence base on young children’s early learning, development and well‑being. The study provides internationally comparable information on the skills, competencies and experiences of five‑year‑old children, supporting countries and jurisdictions in designing and evaluating policies that foster positive developmental outcomes. This report is the product of extensive collaboration and co‑operation among many stakeholders and contributors. In particular, the co‑operation of staff and leaders in the participating early learning settings was essential to the successful implementation of IELS.
IELS was implemented under the Programme of Work and Budget of the OECD Education Policy Committee (EDPC).
Participating countries and jurisdictions implemented IELS at the national or subnational level through national project centres, supported by national project managers (NPMs), national data managers (NDMs) and national sampling managers (NSMs). These teams operated under rigorous technical and operational standards. NPMs played a central role in securing participation from early learning settings, overseeing the national adaptation, translation and validation of study instruments, managing national data collection and processing, and verifying the accuracy of national results. NDMs coordinated national data processing and data cleaning, while NSMs ensured that sampling procedures and all technical requirements were rigorously followed.
In addition to the participating countries and jurisdictions, several experts contributed to developing the assessment instruments. A Technical Expert Group (TEG) supported the decision‑making process on technical and analytical matters. Subject‑matter experts and analysts also played a critical role in the analytical phase and in drafting the initial reports.
At the international level, the co‑ordination and management of the study implementation were the responsibility of the appointed contractors. The Consortium was led by the Australian Council for Educational Research Limited (ACER), together with its partners, the International Association for the Evaluation of Educational Achievement (IEA) and cApStAn Linguistic Quality Control.
The OECD Secretariat had overall responsibility for managing the project, monitoring its day‑to‑day implementation and serving as the secretariat of the Steering Group on IELS.