QA-based metric that measures the faithfulness of the generated text is consisted of three parts:
First, given a generated text, a question generation (QG) model generates a set of question-answer
pairs. Second, a question answering (QA) model answers the generated questions given a ground-
truth source text as the reference (containing knowledge). Lastly, the hallucination score is computed
based on the similarity of the corresponding answers.

Similar to the IE-based metrics, the limitation of this approach is the potential error that might
SurveyofHallucinationinNatural Language Generation