Beyond Known Event Types: Open-Domain Event Detection via Ontology-Guided Grounding–Discovery Resolution
Real-world event detection systems rarely work with a complete list of event types — new kinds of events keep emerging. When an event type is missing from the predefined set, existing zero-shot detectors either miss the event entirely or force it into a plausible but wrong known type, silently hiding the need for discovery. We propose OGED, an ontology-guided framework that treats known-type assignment and new-type discovery as competing explanations and resolves them jointly before output. On a unified benchmark with 564 event types, OGED substantially improves both known-type detection and unknown-type discovery over strong baselines.






