Education in Wales: our national mission 2017-2021 set out the Welsh Government’s plans ‘to raise standards, reduce the attainment gap and deliver an education system that is the source of national pride and confidence’ (Kirsty Williams, Cabinet Secretary for Education). In order to achieve this, four enabling objectives have been identified: developing a high-quality education profession; inspirational leaders working collaboratively to raise standards; strong and inclusive schools committed to excellence, equity and well-being; and robust assessment, evaluation and accountability arrangements supporting a self-improving system. A major feature of this is to ensure decisions are ‘evidence-driven’. This requires the collection of new data (e.g. “effective learner, workforce and parental surveys” (p.32), benchmarking against progress and with other international partners, and the effective use of routinely collected data on learners. Data is therefore seen as an important enabler for improving the education system in Wales. However, with the proliferation and increasing availability of educational data it can also become a burden. It is important that such data are contextualised, assessed for quality and used appropriately. Data should also be used transparently and shared for critique and debate. An independent data lab will be essential in lifting some of this burden from the sector and in providing leadership in its use. The risks in not delivering this are considerable. The absence of such a resource will increase the likelihood of making un-informed decisions, using data to mislead, and eventually rejecting the value of data, and evidence more generally, within the education system.