faithfulness-vs-factuality-distinction-maynez-2020

IN premise — summaries/2026/08/24/wiki-Hallucination_artificial_intelligence-chunk-3.md

Created 2026-08-24T17:11:12+00:00

Maynez et al. (2020) distinguish faithfulness (adherence to source text) from factuality (alignment with ground truth) as two independent failure modes in summarization and RAG systems.

Summary

A summarizer or retrieval-augmented system can faithfully repeat a source that is itself wrong, or it can inject correct outside knowledge the source never stated; these are two separate kinds of error, not one. This matters because fixing one does not fix the other, so evaluation and debugging must track adherence to the source and alignment with reality as independent questions.