Reducing named entity hallucination risk to ensure faithful summary generation

Eunice Akani, Benoit Favre, Frederic Bechet, Romain Gemignani


Abstract
The faithfulness of abstractive text summarization at the named entities level is the focus of this study. We propose to add a new criterion to the summary selection method based on the “risk” of generating entities that do not belong to the source document. This method is based on the assumption that Out-Of-Document entities are more likely to be hallucinations. This assumption was verified by a manual annotation of the entities occurring in a set of generated summaries on the CNN/DM corpus. This study showed that only 29% of the entities outside the source document were inferrable by the annotators, leading to 71% of hallucinations among OOD entities. We test our selection method on the CNN/DM corpus and show that it significantly reduces the hallucination risk on named entities while maintaining competitive results with respect to automatic evaluation metrics like ROUGE.
Anthology ID:
2023.inlg-main.33
Volume:
Proceedings of the 16th International Natural Language Generation Conference
Month:
September
Year:
2023
Address:
Prague, Czechia
Editors:
C. Maria Keet, Hung-Yi Lee, Sina Zarrieß
Venues:
INLG | SIGDIAL
SIG:
SIGGEN
Publisher:
Association for Computational Linguistics
Note:
Pages:
437–442
Language:
URL:
https://aclanthology.org/2023.inlg-main.33
DOI:
10.18653/v1/2023.inlg-main.33
Bibkey:
Cite (ACL):
Eunice Akani, Benoit Favre, Frederic Bechet, and Romain Gemignani. 2023. Reducing named entity hallucination risk to ensure faithful summary generation. In Proceedings of the 16th International Natural Language Generation Conference, pages 437–442, Prague, Czechia. Association for Computational Linguistics.
Cite (Informal):
Reducing named entity hallucination risk to ensure faithful summary generation (Akani et al., INLG-SIGDIAL 2023)
Copy Citation:
PDF:
https://aclanthology.org/2023.inlg-main.33.pdf
Supplementary attachment:
 2023.inlg-main.33.Supplementary_Attachment.pdf