Private Health Journal

Glossary · Evaluation and safety

Hallucination

confabulation · fabrication

Hallucination

Established

Output that is fluent and plausible but not supported by the input or by any real source.

In medicine the failure mode is asymmetric: a fabricated dose or citation reads exactly like a correct one.

Context

SourceNature Medicine and npj Digital Medicine, evaluations of clinical LLM outputs — verification required