This article provides results from a study of the hidden processes of consensus formation that precede and make possible official judgments and decisions of the Swedish Schools Inspectorate (SI). The research question for the study was: How is knowledge negotiated on the back stage of school inspection and presented on the front stage? The article builds on in-depth case studies of school inspection in four schools. Data include internal and official material from SI, on-site observations of inspection in schools and internal quality assurance meetings at SI, and interviews with inspectors. The analysis is inspired by Goffman's usage of the concepts "front stage" and "back stage." The results suggest that the SI front stage borrows legitimacy from an evidence-based model aiming at objective and "equivalent" judgments, while the back stage displays a complex mix of rigorous formalized guidance and uncertainty that requires inspectors' brokering and deliberation.