This concluding essay offers a reflection on the set of the papers contained in this special issue of the Educational Assessment journal. In it the author situates formative assessment squarely in the realm of teachers' continuous professional learning and considers the essential nature of formative assessment as centering on three questions that guide the practice for both teachers and students: where are the students going (well-defined learning goals), where are they currently (evidence collected during the course of learning), and how to close the gap between these two (instructional adjustments, feedback, and student involvement)? The author returns at the end to note the importance of professional learning in the context of formative assessment.