Assessment has long been at the center of education policy debates, and for good reason. The goal of schooling is to maximize student learning, and assessments provide a picture of what students know and are able to do. Assessments also have a strong influence on what goes on in classrooms. The United States is now poised to make the most dramatic advance in assessment in decades. A state-led effort to develop common core standards in literacy and mathematics is defining what it means to be ready for colleges and careers, and this effort will invariably heighten the demand for assessments that measure a broader range of knowledge and skills and open the door for common assessment components across states. At the same time, the U.S. Department of Education is providing $350 million for consortia of states to develop new assessments that measure the common core standards. And a reauthorization of the Elementary and Secondary Education Act (ESEA) will set guidelines for assessments and their use for years to come. This brief suggests the principles upon which the federal government and states should base their work in fashioning new assessments. Recognizing that no single test can fulfill all the needs for information by all stakeholders, it suggests the need for a comprehensive system of assessments. Most importantly, the brief argues that this system needs to be coherent and cohesive, aligned to standards for college and career readiness. (Contains 1 figure and 9 endnotes.)