Despite the value of the comparative perspective for the study of higher education is widely recognised, there is little consensus about the specific methodological approaches. Quantitative tools outlined their relevance for addressing comparative analyses since they are supposed to reducing the complexity, finding out and graduating similarities and differentiations, and improving the generalization of the results. Nevertheless, the limited availability of comparative data hampers statistical comparative analyses, and data and statistics might be seen just as complementary analytical tools. This paper has a twofold aim. Firstly, it addresses key methodological problems for accurate international comparisons in higher education studies. Secondly, the article discusses the difficulties encountered in using measurements in comparative studies, and issues to be addressed in order to improve the robustness of the method and the possibility of using quantitative tools.