Hallucination

Updated 2026-09-15

A hallucination is an AI-generated statement presented confidently but unsupported by any retrieved source or by fact. In brand terms it usually appears as an invented feature, an outdated price, or a capability attributed to the wrong product.

How it shows up in brand answers

Three patterns account for most brand hallucinations. Memory answers describe a product as it was in the training data, which is often a year stale. Ambiguous names cause attribute transfer between similarly named products. And thin documentation invites the model to fill gaps with category defaults — if your page never states what you do not do, the model may assume you do. Measurement means reading sampled answers, not only counting mentions.

Illustrative case (example, not a customer measurement)

Five of thirty sampled answers describe a product as having a free tier it has never had. Four of the five were ungrounded memory answers; the fifth cited a two-year-old review. The correction is a current, explicit pricing statement plus an outreach to the stale source — not a change to the prompt set.

Common mistakes

  • Counting a hallucinated mention as visibility. A wrong description can be worse than absence.
  • Fixing only your own page when the error is being carried by a third-party source engines prefer.
  • Assuming a correction propagates immediately — engines re-crawl and re-summarise on their own schedule.

Frequently asked questions

Can hallucinations about our brand be prevented?
Not eliminated, but they can be starved: current, explicit, easily retrievable statements about what the product is and is not leave less room for the model to guess, and grounded answers hallucinate markedly less than memory answers.
Should hallucinations be tracked as a metric?
They should be read rather than scored. Sampling answers and recording factual errors as a list gives you something actionable; a "hallucination rate" invites arguing about the denominator.

Related terms