[Introduction] International comparative higher education research has proliferated since its institutionalization as an interdisciplinary field in the 1960s and 1970s (Jarausch 1985) and has gained special momentum in the 1990s (Teichler 1996). On the one hand, the benefits of comparative research approaches in international higher education have been repeatedly emphasized (Altbach and Kelly 1985; Teichler 1996; Rhoades 2001). These include, for example, increasing the capacity to generalize about a greater number of units under analysis, the capacity of a systematic comparison to illuminate the dynamics of a particular system better than a single-system study as well as highlighting knowledge gaps. On the other hand, methodological debates about comparing higher education internationally and how best to compare them emerged hand-in-hand with the field’s growth in popularity. Although the logic of international comparative research does not differ from research undertaken just within one country (Teichler 1996; Goedebuure and Van Vught 1996), some problems are posed in an especially complicated and intractable fashion (Hantrais 2009; Smelser 1976/2013), because of the focus on units that are dissimilar as well as similar (to be comparable). This poses specific challenges to international comparative research. [Continues, please see the article]