This chapter examines how formative assessment – frequent, interactive assessments of student understanding and progress to identify learning needs and shape teaching – can help countries realise both quality and equity in educational outcomes. Between 2002 and 2004, the OECD examined formative assessment policy and practice in exemplary classrooms in lower secondary schools in eight systems (Australia [Queensland], three Canadian provinces, Denmark, England, Finland, Italy, New Zealand and Scotland). Formative Assessment: Improving Learning in Secondary Classrooms (OECD, 2005) also included reviews of English-, French- and German-language literature on formative assessment.