2026

Behavioral problems in deployed LLMs are often discovered when only limited supervision is available and repeating full alignment training is impractical. Existing post-hoc methods have complementary limitations: activation steering lacks input adaptivity, while standard LoRA learns without an explicit behavioral direction prior and can be unstable in low-data settings. We introduce PR-LoRA, a direction-regularized LoRA variant that initializes LoRA B matrices with per-layer contrastive behavioral directions and anchors them with an L2 penalty, while leaving A freely trainable. We evaluate PR-LoRA on seven CAA behaviors across Qwen3 and LLaMA models against activation steering and parameter-efficient adaptation baselines. On Qwen3-8B, PR-LoRA lowers the seven-behavior macro-average undesirable-behavior score from .405 to .374 relative to standard LoRA, a 7.8% relative reduction, and outperforms DPO-LoRA and LoReFT under the tested low-update budget.
Maintaining persona consistency across multi-turn dialogues remains a core challenge for role-playing language models. Off-policy distillation from external teachers incurs distribution mismatch that compounds across dialogue turns, while reinforcement learning struggles with reward ambiguity inherent in subjective persona fidelity. We propose OSPD, an on-policy self-distillation framework where the same model serves as both teacher and student under asymmetric information: the teacher receives a complete character profile while the student sees only a brief summary, and the student generates trajectories from its own policy. We find that teacher confidence in role-playing dialogue exhibits a bimodal structure—sharply peaked at character-critical tokens yet diffuse at generic utterances—and introduce role-aware divergence switching to match this structure. A progressive trait masking curriculum further forces staged internalization of character knowledge along semantic dimensions. Experiments on CharacterBench, CharacterEval, and SocialBench show that OSPD substantially improves persona consistency over supervised fine-tuning and multi-turn RL baselines, without requiring any external teacher or reward model.

2022

Existing research for argument representation learning mainly treats tokens in the sentence equally and ignores the implied structure information of argumentative context. In this paper, we propose to separate tokens into two groups, namely framing tokens and topic ones, to capture structural information of arguments. In addition, we consider high-level structure by incorporating paragraph-level position information. A novel structure-aware argument encoder is proposed for literature discourse analysis. Experimental results on both a self-constructed corpus and a public corpus show the effectiveness of our model. Resources are available at https://github.com/lemuria-wchen/SAE.