Diversity is defined as those numerous elements of difference between groups of people that play significant roles in social institutions, including (but not limited to) race and ethnicity, gender, socioeconomic class, sexual orientation, and culture. Since doctoral degree recipients go on to assume roles as faculty and educators, diversity in doctoral programs is significant. By supporting graduate diversity across the academic disciplines, universities ensure that the nation s intellectual capacities and opportunities are fully realized. The authors consider diversity broadly from multiple perspectives, from race and ethnicity to institutional type, academic discipline, and national origin. They demonstrate how diversity operates through these venues and definitions, and hope to stimulate a conversation about a key aspect of American higher education. This volume is the 163rd volume of the Jossey-Bass quarterly report series New Directions for Higher Education. Addressed to presidents, vice presidents, deans, and other higher education decision makers on all kinds of campuses, New Directions for Higher Education provides timely information and authoritative advice about major issues and administrative problems confronting every institution.