Hallucination
Also known as: hallucinate · confabulation
A hallucination is a confident, fluent statement that is false or invented. The model isn’t “lying” — it’s a next-token-predictor, and sometimes the most likely-sounding continuation is just not true.
Common shapes:
- Inventing facts, dates, or citations.
- Claiming a capability it doesn’t have.
- Confidently misquoting a source.
RAG and citations exist largely to reduce them by grounding answers in real documents.
Working with it: treat model output as *a draft to verify*, especially for facts, numbers, and quotes. Never paste unverified model output into something that ships.