Decoder. plain-English AI glossary

Confabulation

▲ Rising

Also called Confabulation

A more precise name for hallucination — the model fills a gap with a fluent, made-up detail rather than lying.

Think of it like

A person with memory gaps who unconsciously invents plausible details to bridge them, fully believing the story.

Example

Asked for a citation it doesn’t have, the model produces a real-sounding author, title, and year — none of which exist.

How it actually works

Some researchers prefer "confabulation" over "hallucination" because it captures the mechanism better: the model isn’t perceiving things that aren’t there, it’s smoothly generating a likely-sounding filler when it lacks the fact. It’s not intent to deceive — it’s pattern completion where "plausible" stands in for "true." The framing matters because it points to the fix: give the model the fact, and it stops needing to invent one.

For product teams

Reframes "the AI lied" as "the AI guessed fluently" — which points the fix toward retrieval, not scolding.

For engineers

Ungrounded generation fills missing information with high-likelihood tokens; mitigate by supplying the fact via retrieval.

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