Rethinking the Evaluation of Alignment Methods: Insights into Diversity, Generalisation, and Safety

Denis Janiak, Julia Moska, Dawid Motyka, Karolina Seweryn, Paweł Walkowiak, Bartosz Żuk, Arkadiusz Janz


Abstract
Large language models (LLMs) require careful alignment to balance competing objectives: factuality, safety, conciseness, proactivity, and diversity. Existing studies focus on individual techniques or specific dimensions, lacking a holistic assessment of the inherent trade-offs. We propose a unified evaluation framework that compares LLM alignment methods (PPO, DPO, ORPO, KTO) across these five axes, using both in-distribution and out-of-distribution datasets. Leveraging a specialized LLM-as-Judge prompt, validated through human studies, we reveal that DPO and KTO excel in factual accuracy, PPO and DPO lead in safety, and PPO best balances conciseness with proactivity. Our findings provide insights into trade-offs of common alignment methods, guiding the development of more balanced and reliable LLMs.
Anthology ID:
2026.eacl-srw.7
Volume:
Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 4: Student Research Workshop)
Month:
March
Year:
2026
Address:
Rabat, Morocco
Editors:
Selene Baez Santamaria, Sai Ashish Somayajula, Atsuki Yamaguchi
Venue:
EACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
92–109
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URL:
https://preview.aclanthology.org/ingest-eacl/2026.eacl-srw.7/
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Bibkey:
Cite (ACL):
Denis Janiak, Julia Moska, Dawid Motyka, Karolina Seweryn, Paweł Walkowiak, Bartosz Żuk, and Arkadiusz Janz. 2026. Rethinking the Evaluation of Alignment Methods: Insights into Diversity, Generalisation, and Safety. In Proceedings of the 19th Conference of the European Chapter of the Association for Computational Linguistics (Volume 4: Student Research Workshop), pages 92–109, Rabat, Morocco. Association for Computational Linguistics.
Cite (Informal):
Rethinking the Evaluation of Alignment Methods: Insights into Diversity, Generalisation, and Safety (Janiak et al., EACL 2026)
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https://preview.aclanthology.org/ingest-eacl/2026.eacl-srw.7.pdf