Model Internals-based Answer Attribution for Trustworthy Retrieval-Augmented Generation

Jirui Qi, Gabriele Sarti, Raquel Fernández, Arianna Bisazza


Abstract
Ensuring the verifiability of model answers is a fundamental challenge for retrieval-augmented generation (RAG) in the question answering (QA) domain. Recently, self-citation prompting was proposed to make large language models (LLMs) generate citations to supporting documents along with their answers. However, self-citing LLMs often struggle to match the required format, refer to non-existent sources, and fail to faithfully reflect LLMs’ context usage throughout the generation. In this work, we present MIRAGE – Model Internals-based RAG Explanations – a plug-and-play approach using model internals for faithful answer attribution in RAG applications. MIRAGE detects context-sensitive answer tokens and pairs them with retrieved documents contributing to their prediction via saliency methods. We evaluate our proposed approach on a multilingual extractive QA dataset, finding high agreement with human answer attribution. On open-ended QA, MIRAGE achieves citation quality and efficiency comparable to self-citation while also allowing for a finer-grained control of attribution parameters. Our qualitative evaluation highlights the faithfulness of MIRAGE’s attributions and underscores the promising application of model internals for RAG answer attribution. Code and data released at https://github.com/Betswish/MIRAGE.
Anthology ID:
2024.emnlp-main.347
Volume:
Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2024
Address:
Miami, Florida, USA
Editors:
Yaser Al-Onaizan, Mohit Bansal, Yun-Nung Chen
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
6037–6053
Language:
URL:
https://aclanthology.org/2024.emnlp-main.347
DOI:
Bibkey:
Cite (ACL):
Jirui Qi, Gabriele Sarti, Raquel Fernández, and Arianna Bisazza. 2024. Model Internals-based Answer Attribution for Trustworthy Retrieval-Augmented Generation. In Proceedings of the 2024 Conference on Empirical Methods in Natural Language Processing, pages 6037–6053, Miami, Florida, USA. Association for Computational Linguistics.
Cite (Informal):
Model Internals-based Answer Attribution for Trustworthy Retrieval-Augmented Generation (Qi et al., EMNLP 2024)
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https://aclanthology.org/2024.emnlp-main.347.pdf
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