International large-scale assessments (ILSAs) have had an increasing influence on the discourse surrounding education systems around the world. However, the results of these studies tend to have less impact on pedagogy in the classroom than would be expected. For example, a recent review of 114 published peer-reviewed articles on the IEA's Progress in International Reading Literacy Study (PIRLS) indicated that PIRLS is not often used to inform reading research, which could be one reason for its low impact on pedagogy in the classroom (Lenkeit et al., 2015). Teachers often lack knowledge about ILSAs (Popat et al., 2017). Previous studies have indicated teachers struggle to make sense of assessment data (Young, 2006) beyond general findings. In the case of ILSAs, such general findings are normally restricted to aggregated country rankings. Educators' poor assessment literacy often leads to confusion about how ILSA data can and should be used to inform their pedagogy. In this policy brief, the authors present findings from the PIRLS for Teachers project, designed to improve teachers' assessment literacy and knowledge of PIRLS. In 2015, teachers from four schools in England worked closely with researchers from Oxford University to develop strategies for interpreting and using the knowledge from PIRLS 2011 to improve teaching of reading in primary schools.