In absence of a better answer, I would say that a system has a world-model if it can answer various questions about the world mostly coherently (i.e. the answers to two different questions should not make completely different assumptions about something).
In absence of a better answer, I would say that a system has a world-model if it can answer various questions about the world mostly coherently (i.e. the answers to two different questions should not make completely different assumptions about something).