arXiv Computation and Language By Koshiro Saito, Diasuke Oba, Danushka Bollegala, Naoaki Okazaki

Beyond Model Weights: Sampling-Dependent Fairness in Diffusion Language Models

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Diffusion language models (DLMs) are gaining traction as an alternative to autoregressive language models, but their fairness has not been well studied. This work investigates how sampling controls—such as block length and remasking strategy—affect social bias in three DLMs (LLaDA, LLaDA‑1.5, and Dream on Open‑BBQ). The authors find that both the magnitude of bias and the relative ranking of models vary significantly with sampling settings, and that even after applying mitigation strategies from autoregressive models, sampling dependence remains, indicating that fairness in DLMs cannot be assessed independently of sampling configuration.

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