In AI, hallucination refers to output that is confidently stated but factually incorrect, fabricated, or unsupported by the model's training data.
Hallucination is a known limitation of language models. Because these models predict plausible text rather than retrieving verified facts, they can produce statements that sound authoritative but are wrong — including fabricated citations, incorrect dates, and invented facts.
What to do
Treat AI-generated factual claims as drafts requiring verification, not as authoritative sources. For high-stakes decisions, always verify against reliable primary sources.