> ## Documentation Index
> Fetch the complete documentation index at: https://wiki.platelunchcollective.com/llms.txt
> Use this file to discover all available pages before exploring further.

# Hallucination

> 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.

*Core concept* · *AI Search Infrastructure*

## Definition

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.

## Why It Matters for AI Search

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offering, or leadership is typically expressing a high-confidence parametric belief formed from sparse, conflicting, or outdated training data — not generating random noise.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.

## Common Misconception

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.

## Related Terms

<CardGroup cols={2}>
  <Card title="Parametric knowledge" href="/ai-search-glossary/parametric-knowledge" />

  <Card title="Parametric belief" href="/ai-search-glossary/parametric-belief" />

  <Card title="Hallucination mitigation" href="/ai-search-glossary/hallucination-mitigation" />

  <Card title="Grounding" href="/ai-search-glossary/grounding" />

  <Card title="Knowledge conflict" href="/ai-search-glossary/knowledge-conflict" />

  <Card title="Training corpus" href="/ai-search-glossary/training-corpus" />
</CardGroup>

## Relevant Plate Lunch Collective Services

[Entity SEO](https://www.platelunchcollective.com/services/entity-seo)  [Context Map](https://www.platelunchcollective.com/services/context-map)  [AI Search Visibility Assessment](https://www.platelunchcollective.com/services/consulting/ai-search-visibility)