Title: Towards Evaluation for Real-World LLM Unlearning
Primary area: alignment, fairness, safety, privacy, and societal considerations
Keywords: machine unlearning, large language model, evaluation metric

Abstract: This paper analyzes the limitations of existing unlearning evaluation metrics in terms of practicality, exactness, and robustness in real-world LLM unlearning scenarios. In addition, the differences between core tokens and non-core tokens are revealed in unlearning. To overcome these limitations, we propose a new metric called Distribution Correction-based Unlearning Evaluation (DCUE). It identifies core tokens and corrects distributional biases in their confidence scores using a validation set. The final evaluation results are quantified using the Kolmogorov–Smirnov test. Experimental results demonstrate that DCUE overcomes the limitations of existing metrics, which also guides the design of more practical and reliable unlearning algorithms in the future.