Trident: Self-Supervised Preference Alignment via Triplet Regularization

Yingnan Guo, Kejia Chen, Xiaofeng Zhang, Zifei Wu, Yu Zhang


Abstract
Aligning Large Vision-Language Models (LVLMs) to mitigate hallucinations typically relies on high-quality preference data. However, in self-supervised settings, standard binary preference optimization (e.g., DPO) suffers from noisy supervision and semantic ambiguity, as automatically generated chosen responses are not guaranteed to be superior to rejected ones. In this work, we propose Trident, a fully self-supervised framework that ensures robust alignment via a structured triplet paradigm. Trident autonomously constructs reliable preference triplets—comprising semantically enriched (chosen), degraded (rejected), and neutral (anchor) responses—through automated visual perturbations and self-summarization. We further introduce Trident Preference Regularization (TPR), a novel objective that utilizes an adaptive margin to enforce semantic separation between the triplet components while preventing deviation from the pretrained distribution. Despite requiring no human annotations or external reward models, Trident consistently outperforms state-of-the-art RLHF and RLAIF baselines. For instance, on LLaVA-1.5-7B, it reduces the hallucination rate on AMBER to 11.3% and achieves 95.70% precision on POPE using only 4k self-generated triplets and a single epoch. This validates structured triplet supervision as a scalable paradigm for robust self-supervised alignment.
Anthology ID:
2026.findings-acl.1585
Volume:
Findings of the Association for Computational Linguistics: ACL 2026
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
Findings
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Publisher:
Association for Computational Linguistics
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Pages:
31668–31683
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URL:
https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1585/
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Cite (ACL):
Yingnan Guo, Kejia Chen, Xiaofeng Zhang, Zifei Wu, and Yu Zhang. 2026. Trident: Self-Supervised Preference Alignment via Triplet Regularization. In Findings of the Association for Computational Linguistics: ACL 2026, pages 31668–31683, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
Trident: Self-Supervised Preference Alignment via Triplet Regularization (Guo et al., Findings 2026)
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https://preview.aclanthology.org/ingest-acl/2026.findings-acl.1585.pdf
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