Providing all students with a fair opportunity to learn (OTL) is perhaps the most pressing issue facing U.S. education. Moving beyond conventional notions of OTL - as access to content, often content tested; access to resources; or access to instructional processes - the authors reconceptualize OTL in terms of interaction among learners and elements of their learning environments. Drawing on socio-cultural, sociological, psychometric, and legal perspectives, this book provides historical critique, theory and principles, and concrete examples of practice through which learning, teaching, and assessment can be re-envisioned to support fair OTL for all students. It offers educators, researchers, and policy analysts new to socio-cultural perspectives an engaging introduction to fresh ideas for conceptualizing, enhancing, and assessing OTL; encourages those who already draw on socio-cultural resources to focus attention on OTL and assessment; and nurtures collaboration among members of discourse communities who have rarely engaged one another's work.