Although the art historical canon has been the subject of fierce debate, it remains an essential construct, shaping textbooks and survey courses. Visual representations of the canon often illustrate these narratives. Students encounter diagrams in their studies and it is important to make them aware of the illusion of scientific objectivity. This paper proposes the use of the computer ontology, as a modeling tool with which students can make translations of existing diagrams. This forces them to reconsider the modeling decisions underlying traditional representations. The article takes as its case study the translation of Alfred Barr's diagram of Modern Art, using the free tool "Protégé." An analysis of this process allows us to consider the ambiguous meanings of nodes, relationships and dimensions of the model. Asking students to actively recreate this network of information is shown to be a valuable addition to traditional survey courses on Modern Art.