9.1 Hallucination Definition in GQA
As a challenging yet under-explored task, there is no standard definition of hallucination in GQA.
However, almost all the works on GQA [47, 88, 133, 172] involve a human evaluation process, in
which the factual correctness measuring the faithfulness of the generated answer can be seen as a
measurement of the hallucination; i.e., the more faithful the answer is, the less hallucinated content
it contains. The most recent such work [102] uses the term semantic drift, which indicates how the
answer drifts away from a correct one during generation, and this can also be seen as a specific
definition of hallucination in GQA.
SurveyofHallucinationinNatural Language Generation