States and school districts across the nation are making critical decisions about student assessments as they move to implement the Common Core State Standards (CCSS), adopted by 45 states. The Standards feature an increased focus on deeper learning, or students' ability to analyze, synthesize, compare, connect, critique, hypothesize, prove, and explain their ideas. States are at different points in the CCSS transitions, but all will be assessing their K-12 students against these higher standards in the 2014-15 school year. Based on the changing demands of today's workforce, advances in other nations, and original analysis, this report provides a set of criteria for high-quality student assessments. These criteria can be used by assessment developers, policymakers, and educators as they work to create and adopt assessments that promote deeper learning of 21st- century skills that students need to succeed in today's knowledge-based economy.