A model output that presents false, fabricated, or unverifiable information as factual — plausible in form but not grounded in accurate training data or retrieved evidence.
A hallucination is a model output that presents false, fabricated, or unverifiable information as factual. Hallucinations occur when a model generates a response that is plausible in form — coherent, confident, and well-structured — but not grounded in accurate training data or retrieved evidence.
For brands, hallucinations are most often a parametric confidence problem, not a random error. A model that hallucinates a brand’s founding year, service offering, or leadership is typically expressing a high-confidence parametric belief formed from sparse, conflicting, or outdated training data — not generating random noise. The practical implication: hallucinations about a brand are diagnosable and addressable through the same interventions that fix any wrong parametric representation. Hallucination mitigation at the platform level — through retrieval-augmented generation and grounding requirements — reduces but does not eliminate brand misrepresentation, particularly for the share of queries answered from parametric memory without retrieval.
Hallucinations are random and unpredictable. For brand-relevant claims, they are typically systematic — the model consistently produces the same wrong answer because it consistently holds the same wrong belief with high confidence.