The Australian Council for Educational Research (ACER) has participated in the debate about the use of assessment data in education for many years. The Brookings report “Use of data from 21st century skills assessments: Issues and key principles” helps shape a reform agenda that ACER also seeks to promote. Research on the definition and description of skills deemed essential for citizens and employees, greater emphasis on reconceptualizing existing curriculum domains, and capacity building work through initiatives such as the Brookings-led Optimizing Assessment for All project will inform the feasibility of using a data-driven approach to assessment development within and across countries, as well as investigating the generalizability of 21st century skills across subject areas and locations.