Enhancing Persona Consistency for LLMs' Role-Playing using Persona-Aware Contrastive Learning
Journal:
arXiv
Published Date:
Mar 22, 2025
Abstract
In recent years, large language models (LLMs) have achieved breakthrough
progress in many dialogue generation tasks. However, their lack of emotion and
fine-grained role awareness limits the model's ability to provide personalized
and diverse interactions further. Current methods face high costs in collecting
high-quality annotated data for scenarios such as role-playing, and traditional
human alignment methods are difficult to deploy due to the inherent diversity
of model behavior in role-playing scenarios. Inspired by the alignment of
models for safety behaviors through RLHF (Reinforcement Learning from Human
Feedback), in this paper, we revisit model role-playing behavior from the
perspective of persona alignment and propose a novel annotation-free framework
named \textbf{\underline{P}}ersona-Aware \textbf{\underline{C}}ontrastive
\textbf{\underline{L}}earning (PCL) to align LLMs' behavior during
role-playing, enhancing the model's role consistency. Specifically, we first
design a role chain method to encourage the model to self-question based on the
role characteristics and dialogue context to adjust personality consistency.
Then, we further enhance the model's role-playing strategy through iterative
contrastive learning between the use of role characteristics and not.
Experiments on both black-box and white-box LLMs show that LLMs equipped with
PCL significantly outperform vanilla LLMs under automatic evaluation methods
(CharEval \& GPT-4) and human expert evaluation.
