Norway has seen major changes in the field of educational assessment over the past decade, following the 2001 '"PISA shock" that stimulated reform of the entire primary and secondary education systems: new outcome-based curricula with cross-disciplinary basic skills were accompanied by major revision of assessment regulations, comprehensive government projects promoting formative assessment, national tests as a main component in a new national quality assessment system and new regulations for examinations and teacher reporting of overall achievement marks. The paper provides a historical context to the country's prohibition of formal marking in primary education and the recent tensions determining how assessment criteria should be stated and used for formative and summative purposes. It is argued that Norwegian primary and secondary education is riddled with unresolved tensions as to the role of assessment criteria and national tests, sparked by incremental implementation of assessment policies and principles accompanying the new outcomes-based curricula.