arXiv Computation and Language By Tyler Lizzo, Larry Heck

Behavioral Forgetting Is Not Privacy in Machine Unlearning

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The paper argues that machine unlearning, which seeks to erase specific information from large language models, is often evaluated only on a single benchmark distribution, leading to an incomplete assessment of privacy. The authors demonstrate that forgetting can differ significantly when the same information is queried in different languages and scripts across multilingual models, revealing a gap between behavioral forgetting and true inaccessibility. They call for broader evaluation that includes access‑path generalization and adversarial recoverability to ensure genuine privacy protection.

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