Independent schools have long been searching for better ways to prove their value, and in a data-centric world, there is enormous pressure to measure, measure, measure, and abide by partially obsolete college entrance requirements. Yet there is a strong consensus that the majority of currently used large-scale assessments are not comprehensive enough to measure what really counts for 21st-century student success for life, including, but not limited to, employability. To deeply reexamine the content focus of assessment as well as the methods and their strengths and weaknesses, the Center for Curriculum Redesign (CCR) created the Assessment Research Consortium (ARC), of which the National Association of Independent Schools (NAIS) is a founding member. The overall goal is to deepen the relationship between learning and assessment, and move from sorting students toward continuous improvement of all aspects of the learning experience. In fact, it may be useful to redefine assessment to mean, more broadly, any source of evidence of learning. In this article, the authors promote their research showing that the future content of student assessments will draw from modern and traditional disciplines.