By analysing five separate OECD reviews of evaluation and assessment practices with Norway and Sweden as cases, our study illustrates different ways in which a specific international educational reasoning is blended into more context-based national education policies and, as such, works in parallel with internal reforms and agendas. It is evident that an overarching narrative promotes the importance of coherent and integrated systems of evaluation and assessment in order to strengthen social and political endeavours for equity, quality and achievements. The parallel mix of OECD discourses and national discourses creates a combined narrative in which evaluations and assessments appear natural, self-evident and rational as well as highly adaptable to national settings. The study shows that national vertical and/or horizontal developments are intertwined with the OECD policy recommendations, which are quite general in character. In a continuing process of uploading and downloading, within different contexts, policies are elaborated and recontextualised. Evaluations and assessments are part of a contemporary rational paradigm for mapping and promoting performance in national educational systems--what we identify as a comparative curriculum code.