Rankings of international higher education institutions have become influential, newsworthy metrics worldwide. This is unsurprising given the rising prevalence of cross-national college attendance. This report evaluates the methodologies of three major international ranking systems: the Academic Ranking of World Universities (ARWU, or "Shanghai Rankings"), the Times Higher Education World University Rankings (THE), and the Quacquarelli Symonds World University Rankings (QS). This report serves as an addendum to NORC's prior report (Barari et al., 2024). Issues identified with domestic rankings in the U.S. also apply to international systems, with some additional challenges particular to the international case: (1) There are inherent challenges to cross-national standardization and comparability; (2) There are many layers of subjectivity in international rankings; and (3) The intended purpose of each ranking is not clear. This report offers several key recommendations to address these challenges. [This report was produced by NORC Research Science.]