While the SDGs now officially call for global reporting on learning outcomes, many institutions and scholars had noticed, at least since the mid-2000s, that many children were not learning much, and were starting to respond by, as a first step, advocating and developing assessments that, they felt, was perhaps more appropriate to learning at the bottom of the pyramid, or at the left end of the cognitive distribution. The GMR sounded a clarion with their estimate that there are some 250 million children in the world hardly learning. This paper addresses an issue that can be put simply but is extremely hard to answer: “Is the array of assessments emerging helping researchers, policy-makers, and implementers get a more accurate sense of how much or how little the poorest children in the world know, and is it helpful in remediating the situation?” The paper specifically is not addressed at the question of global reporting—although it does touch upon the issue. The problem of interest here is what is most useful for countries to generate movement along the bottom of the pyramid.