In today's education environment, decision making based on data-driven evidence has become part of expected professional practice. If teachers and principals can interpret the data to identify learning needs, then it becomes possible to adapt teaching in a highly targeted way. However, analysing and interpreting quantitative data in the context of a school setting is not easy, and teachers now require a level of statistical competence not expected in the past. Teachers do not necessarily need the deep knowledge of statistical algorithms required of statisticians, but they certainly need appropriate levels of statistical literacy: sufficient understanding of numeracy, statistics, and data presentation to make valuable use of quantitative data and summary reports in a personal or professional setting. A research project has examined the statistical literacy that teachers require to make sense of the statistical reports now provided to schools by education systems. The project has also examined teachers' attitudes towards the data, in particular the extent to which they see it as a means to improve student learning.