This report addresses the more contentious aspects of large-scale learning assessments (LSLAs). Drawing on UNESCO's extensive experience in the area from involvement in the direct implementation of assessments and as a knowledge broker and convener of networks this publication presents the Organization's critical take on such initiatives. It aims to balance the debate on LSLAs by reviewing their benefits while raising awareness on their potential risks and pitfalls. The focus of discussions in this publication is on LSLAs conducted in formal and school-based education. It includes an Annex outlining key international studies. [Executive summary, ed]