Open World vs Closed World for Completeness - Gnorion/BizVR GitHub Wiki

Closed World Assumption (CWA) reasoning is a generally accepted requirement in model-driven systems.

Conversely, DL reasoners usually work under the Open World Assumption (OWA). This means that the facts asserted in the model (about the layout topology or the authorization policies) are not assumed to be complete.

What is the difference between CWA and OWA?

The OWA limits the kinds of inference and deductions an agent can make to those that follow from statements that are known to the agent to be true. In contrast, the closed world assumption allows an agent to use the lack of knowledge that a statement is true, to infer that the statement is false.