Ontologies in Arches¶
Arches data is modeled with graphs. A graph is a collection of nodes, structured like branches, all emanating from the root node, which represents the resource itself. If you are modeling a building resource, you may have a root node called “Building” with a node attached to it called “Name”. You can imagine that complex and thoroughly documented resources will have many, many nodes.
An ontology is a set of rules that categorizes these nodes into classes, and dictates which classes can be connected to each other. It’s a “rulebook” for graph construction. Generally, this is known as a CRM (Conceptual Reference Model), and Arches comes preloaded with the CIDOC CRM v6.2, an ontology created by ICOM specifically to describe cultural heritage data. To learn more about the CIDOC CRM, visit cidoc-crm.org or view a full list of classes and properties.
When creating Resource Models and Branches, users have the option of enforcing an ontology throughout the graph, or creating a graph with no ontology. If an ontology is chosen, the Graph Designer will enforce all of the applicable node class (CRM Entities) and edge (CRM Properties) rules during use of the Graph Designer. Importantly, if a Resource Model uses an ontology one can only add Branches to it that have been made with the same ontology.