This study looks at assessment of PhD theses from two perspectives: criteria in use in assessment reports at a science faculty and norms of science. Fifty assessment reports were analysed inductively, resulting in thirteen categories that examiners consider when assessing a thesis. These categories were compared with norms of science as described in the sociology of science. The study shows a high congruence between the two perspectives, but also new categories worthy of further discussion and research. Relevance of the thesis research and quality by proxy (that publication is an indicator of quality) stand out very clearly in this study compared with earlier assessment research. These two categories are both relatively new categories in assessment research and indicate that the classical norms of science are changing with an increasing influence of post-academic norms in academia.