Glossary · Definition
Hallucination
A hallucination is when a language model states something false or unsupported with confidence — an invented fact, citation, policy or number.
By Nythrex EngineeringUpdated 1 min read
In plain words
Language models generate plausible text; plausible isn’t the same as true. When the answer isn’t in the provided context — or the context is missing — models may fill the gap. The fix isn’t hoping for a better model; it’s design: grounding, citations and permission to say “I don’t know”.
When it matters to you
- Any answer users will act on
- Customer-facing assistants
- Legal, financial or medical content
Common pitfalls
- Assuming a bigger model solves it
- No citations, so errors can’t be spotted
- Punishing “I don’t know” answers in evaluation
Keep reading
ServiceRAG developmentRAG development: AI assistants that answer from your documents and data with citations, permissions and measured accuracy — built in your cloud.GuideLLM evals for non-ML teamsHow to evaluate an LLM feature without a data-science team: build a test set, choose metrics, use LLM-as-judge carefully, run evals in CI and read the results.GlossaryGuardrailsGuardrails are the checks and limits around an AI system — on inputs, outputs and actions — that keep it within its intended scope and policies.
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