Queensland adopted a criterion-referenced, school-based assessment system thirty-five years ago, a move that took the focus away from external summative testing and shifted responsibility for assessment to classroom teachers. According to syllabus, policy and other Queensland Studies Authority documents, a central understanding of the system is the complementary nature of formative and summative assessment purposes, with an emphasis on these dual assessment purposes being met by teachers in classrooms. This presentation takes up these ideas as it looks at the presenter's doctoral research examining teachers' formative assessment practices in Year 12 English classrooms. After examining the Queensland system, case studies will be presented to reveal how selected teachers talk about formative assessment, their understandings of its purpose, and their actions in making formative opportunities available to their students. The data indicates that these understandings, and the teachers' practices in relation to formative assessment, are diverse and complex.