Data Augmentation for Improving Contextual Faithfulness Under Knowledge Conflict

Mohith Rajesh, Raj Maheshwari, Vashisth Tiwari, Yonatan Bisk, Emma Strubell, Jeremiah Milbauer, Jared Fernandez


Abstract
External context enables language models to accomplish tasks which rely on information beyond what is captured during pretraining. A standard way to improve contextual faithfulness in these settings is to fine-tune on synthetic, modified questions for which the model must adhere to provided contexts inconsistent with information that may have been seen during training. While this approach reliably improves contextual faithfulness, we find that adapting to a narrowly targeted counterfactual signal yields degradation on other faithfulness evaluations and regression on tasks that evaluate a model’s parametric world knowledge and reasoning. We find that data augmentation, in which a model is trained on both parametrically consistent and counterfactual examples improves performance on faithfulness tasks with reduced regression on parametric world knowledge and reasoning tasks. We find that these improvements are largely consistent across post-training objectives (i.e. SFT, DPO) and across ground-truth, counterfactual data augmentation ratios.
Anthology ID:
2026.findings-aacl.225
Volume:
Findings of the Association for Computational Linguistics: IJCNLP-AACL 2026
Month:
November
Year:
2026
Address:
Hengqin, China
Editors:
Yue Zhang, Ruifeng Xu, Ayu Purwarianti, Tong Rong, Jun Suzuki
Venue:
Findings
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
4419–4431
Language:
URL:
https://aclanthology.org/2026.findings-aacl.225/
DOI:
Bibkey:
Cite (ACL):
Mohith Rajesh, Raj Maheshwari, Vashisth Tiwari, Yonatan Bisk, Emma Strubell, Jeremiah Milbauer, and Jared Fernandez. 2026. Data Augmentation for Improving Contextual Faithfulness Under Knowledge Conflict. In Findings of the Association for Computational Linguistics: IJCNLP-AACL 2026, pages 4419–4431, Hengqin, China. Association for Computational Linguistics.
Cite (Informal):
Data Augmentation for Improving Contextual Faithfulness Under Knowledge Conflict (Rajesh et al., Findings 2026)
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PDF:
https://aclanthology.org/2026.findings-aacl.225.pdf