This document summarizes a project assessing and teaching 21st century skills. The project is a 3-year, university-run and company-sponsored effort to specify measurable 21st century skills, identify barriers to ICT-based assessment, develop and pilot new assessment methods, and recommend classroom-based learning environments and formative assessments. It focuses initially on critical thinking, collaboration, and digital literacy. Researchers are defining assessment tasks and learning progressions to examine proficiency assessment and needed teaching strategies. Multi-stakeholder partnerships across education, government, and industry help contribute to transforming education practice through assessment transformation.