Differentiation, often associated with keywords such as excellence, competition, or diversity, has developed into a key term in higher education policy since the 1980s. This development has gained additional momentum in recent years due to the global discussion about World Class Universities. Differentiation can occur in higher education systems in various forms, and academic as well as higher education policy debates on differentiation follow different lines of discussion. This volume presents selected contributions to the differentiation debate that were presented at the 8th Annual Conference of the Society for Higher Education Research in March 2013 at the Humboldt University in Berlin. The contributions examine this topic from both national and international perspectives, with four aspects being central: the system level.