Hallucination

When an AI model generates content that is factually incorrect, nonsensical, or not grounded in its training data or provided context, presenting false information as fact.

Also known as:AI ConfabulationModel Hallucination

What is AI Hallucination?

AI hallucination refers to instances where a language model generates content that appears plausible but is actually incorrect, fabricated, or not supported by its training data or provided context. The term draws an analogy to human hallucinations - perceiving things that aren't there.

Types of Hallucinations

Factual Errors

  • Incorrect dates, names, statistics
  • Non-existent citations
  • Made-up historical events

Logical Inconsistencies

  • Self-contradicting statements
  • Invalid reasoning chains
  • Impossible scenarios

Confabulation

  • Filling gaps with plausible fiction
  • Inventing details
  • Mixing up related concepts

Why Hallucinations Occur

  • Training data limitations
  • Probabilistic nature of generation
  • Lack of real-time knowledge
  • No inherent fact-checking
  • Optimization for fluency over accuracy

Mitigation Strategies

Technical

  • Retrieval-Augmented Generation (RAG)
  • Grounding with verified sources
  • Uncertainty quantification
  • Chain-of-thought prompting

Operational

  • Human review for critical outputs
  • Citation requirements
  • Confidence thresholds
  • Domain-specific fine-tuning

Detection Methods

  • Cross-reference with known facts
  • Consistency checking
  • Source verification
  • Uncertainty estimation