arXiv AI

DecisionUnlearn-Bench: Unlearning Probabilistic Decisions under Changing Schemas

DecisionUnlearn-Bench is an empirical framework for evaluating machine unlearning in probabilistic decision models, comparing full, unlearned, and retain-only models across various deletion granularities, label renderings, and candidate sets. Experiments on the BANKING77 dataset show that full-to-oracle displacement increases from example to association to class deletion, and that replacing semantic option labels with opaque codes nearly eliminates the retrained oracle’s recognition of deleted classes. The study also highlights variability in unlearning performance across seeds, deletion targets, and datasets, underscoring the importance of reporting effect size, utility, robustness, and recoverability when assessing decision-model unlearning.

arXiv Machine Learning
Oct 16

Not All Change Is Damage: Update-Matched Unlearning for Large Language Models

The paper introduces Update‑Matched Unlearning (UMU), a method that applies the same simulated relearning update to both a defended model and an undefended reference to better preserve plasticity while resisting relearning of deleted knowledge. Experiments on Llama and Qwen models with TOFU and FaithUn datasets show that UMU reduces harmful and benign relearning by 30.4 and 9.9 points on average and increases new‑task accuracy by 3.5 points, supporting the reference‑timing hypothesis. The study demonstrates that robust unlearning should selectively prevent recovery of deleted knowledge without suppressing the model’s ability to learn new tasks.

By Jie Li, Youming Tao, Bowei He, Meng Ding
arXiv Machine Learning
Sep 3

Source-Free Class Relearning: Diagnosing Forgetting in Class Unlearning

The paper investigates whether a model that has undergone class unlearning can still recover forgotten classes without access to original data. It introduces a white‑box audit method that generates synthetic probes in representation space, filters them by confidence, and relabels boundary‑adjacent probes as the forgotten class. The authors define a Relearning Score to quantify recovery while preserving retain performance, and demonstrate that several unlearning techniques on CIFAR‑10, CIFAR‑100, and TinyImageNet can be fully recovered in a source‑free setting, sometimes even outperforming a retrained reference.

By Zahra Dehghani, Pablo Piantanida, Mohammadhadi Shateri
arXiv AI
Aug 24

UpgradeBench: A Decision-Centric Benchmark for Upgrading Fine-Tuned LLM Specialists

UpgradeBench is a decision‑centric longitudinal benchmark that evaluates how fine‑tuned language‑model specialists should be handled when new base‑model releases occur. It covers four consecutive Qwen releases, a continuation checkpoint, six tasks, two model sizes, and OLMo checkpoints with known training lineage, and examines whether retraining, adapter transfer, or other recovery strategies improve specialist performance. The benchmark reveals that upgrade gains vary by task and release interval, that direct adapter copying is sensitive to pretraining distance, and that teacher relabeling can recover specialists without new annotations. "whyItMatters":"The study provides actionable insights into the cost‑effective management of specialist models across model releases, showing how to balance retraining effort with performance gains."

By Ye Chen, Weining Zhang
arXiv Machine Learning
5d ago

Approximate Unlearning in Prototype-based-classifiers

The paper presents a robust approximate unlearning method for Generalized Learning Vector Quantization (GLVQ) classifiers, enabling the removal of specific data samples from trained models. It evaluates how the size and characteristics of the forget set affect unlearning, proposes an adapted technique to mitigate instabilities, and demonstrates that the method achieves near-zero deviation from a fully retrained model while being up to 10^5 times more efficient on benchmark tabular datasets. The approach is applicable to any GLVQ model without altering its training scheme.

By Sreejita Ghosh, Mohammad Mohammadi
arXiv Machine Learning
Sep 10

When Retain Constraints Conflict: Mitigating Forget-Retain Interference in Tabular Data

The paper introduces Conflict-Aware Unlearning (CAU), a schema‑aware method designed to reduce forget‑retain interference in tabular data. CAU relaxes preservation constraints on retained rows that conflict most with the forget set, improving alignment with a retraining oracle while preserving predictive utility. Experiments on clinical and non‑medical tabular tasks demonstrate CAU’s effectiveness for both sample‑level and feature‑level unlearning.

By Zijie Liu, Jinhao Duan, Bingqi Shang, Xinming An, Sijia Liu, Tianlong Chen
arXiv AI
6d ago

Exact Unlearning After Data Curation

The paper investigates what a service must retain to faithfully reproduce a training pipeline after data deletion requests, focusing on a rule where earlier similar records block later ones. It shows that a limit on future deletions precisely determines which records can still be needed for training, enabling an exact repair of training statistics after repeated deletions. The authors also construct finite‑precision features for ridge regression and demonstrate that the required private information can be minimized across a sequence of deletion requests, validating their approach on 1,001 AskUbuntu records.

By Priyank Jayraj, Devanshu sahoo, Uday Mittal
arXiv Machine Learning
Oct 16

What Should We Remove? Evaluating the Reliability and Costs of RLVR Data Decontamination

The study audits 16 open RLVR math corpora, totaling 1,673,514 training items, against six benchmarks with 1,949 questions to assess the reliability and data‑loss costs of decontamination policies. Eight policies—based on exact, lexical, and semantic matching—were evaluated using 594 dual‑reviewed training‑benchmark pairs, with calibration and held‑out sets ensuring disjoint benchmark questions and training‑example families. Results show that at a cosine threshold of 0.80, 88% of sampled removals were false, and no semantic threshold in the tested grid met a 90% conservative‑precision target; however, the judge‑adjudicated policy achieved 98.1% resolved precision and 98.2% recall on held‑out corpora, with no confirmed false removals among six sampled removals.

By Esther Xin