Glossary
What Is an AI Hallucination? Definition and Example
An AI hallucination is a confident answer from an AI that is not true, such as a made-up fact, number, quote or source.
What it means
Hallucinations happen because language models predict plausible text rather than check facts. They are more likely with obscure topics, precise numbers and requests for sources. You can reduce them by supplying the source document, asking for citations and saying 'tell me if you are unsure'.
Example
An assistant cites a research paper that does not exist. Opening the link or searching for the title shows it was invented.
Why it matters
Verifying AI output protects you from errors, especially in finance, health, legal and work documents.
Related terms
- Large Language Model (LLM): A large language model, or LLM, is an AI system trained on huge amounts of text to understand and generate.
- Retrieval-Augmented Generation (RAG): Retrieval-augmented generation, or RAG, is a method where an AI first retrieves relevant documents and then.
- Prompt: A prompt is the instruction or question you give an AI tool. A clear prompt states the role, the context, the.
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Frequently asked questions
Can hallucinations be eliminated?
Not fully. They can be reduced with good prompts, source documents and checking.
How do I spot one?
Check names, numbers, dates, quotes and links against a reliable source.
Do all AI tools hallucinate?
Any tool that generates text can. Tools that show sources make checking easier.