arXiv Machine Learning

Static Gradient Attribution Underperforms a Density-Matched Random Mask on Loss-Based Forgetting Within LoRA B-Matrix

The study examines parameter‑efficient continual learning with LoRA, comparing gradient‑based attribution masks to random masks for selecting adapter parameters. It finds that when both methods are restricted to the same parameter pool, uniform random masks consistently outperform gradient attribution in reducing loss‑based backward transfer across multiple seeds on the Qwen2.5‑3B model, especially on the medical task. This suggests that random masking may better balance stability and plasticity in this setting.

arXiv AI
Jul 22

Soft-TransFormers for Continual Learning

arXiv:2411. 16073v4 Announce Type: replace-cross Abstract: Inspired by the Well-initialized Lottery Ticket Hypothesis (WLTH), we introduce Soft-TransFormers (Soft-TF), a continual learning framework that adapts a frozen pre-trained Transformer through task-specific soft subnetworks: real-valued multiplicative masks over the query, key, value, and output projections of selected self-attention layers.

By Haeyong Kang, Chang D. Yoo
arXiv AI
Jun 3

PURGE: Projected Unlearning via Retain-Guided Erasure

arXiv:2606. 03808v1 Announce Type: cross Abstract: We propose PURGE, a machine unlearning algorithm built on a simple but an under-exploited observation: continual learning (CL) and machine unlearning (MU) which are fundamentally dual problems.

By Vedant Jawandhia, Daksh Ahuja, Ghufran Alam Siddiqui, Prashant Trivedi, Yash Sinha, Pratik Narang
arXiv Machine Learning
Oct 5

Planning to Learn

The paper introduces a new loss function called the horizon loss for training classifiers. It argues that the exact policy gradient used in reinforcement learning is myopic, whereas cross‑entropy is patient, and the horizon loss interpolates between the two by truncating the total error at the remaining learning. Experiments on MNIST and ImageNet with ResNet and ViT models show that horizon loss consistently improves top‑1 accuracy over cross‑entropy, especially when label noise is present.

By Ian Osband
arXiv Machine Learning
5d ago

On the Origin and Evolution of Training-Inference Mismatch in LLM Reinforcement Learning

The paper investigates the training‑inference mismatch that arises when large language models are trained with on‑policy reinforcement learning but inference is performed by a separate engine. It identifies two sources of mismatch—numerical discrepancies in the engine and policy lag due to stale weights—and shows that correcting one source can worsen the other. The authors propose a discrepancy‑lag correction (DLC) that centers numerical errors, clips lag ratios, and resynchronizes the sampler, achieving stable training on Qwen models.

By Yu Li, Yufa Zhou, Tian Lan
arXiv AI
Oct 28

Correcting Before Adapting: Gradient Correction for Federated Adaptive Optimization

The paper introduces Federated Adaptive Gradient Correction (FA‑GC), a method that corrects each gradient before it is incorporated into the running averages used by adaptive optimizers like Adam in federated learning. Compared to a naive correction approach (FA‑NT) that only adjusts the final update direction, FA‑GC ensures that the corrected direction only vanishes at global stationary points and provides convergence guarantees without client‑heterogeneity terms. Experiments on seven image and language tasks show that FA‑GC with Adam achieves target accuracy in fewer rounds and, in some cases, reduces total communication compared to uncorrected local Adam and FA‑NT.

By Evan Chen, Shiqiang Wang, Dong-Jun Han, Shahryar Zehtabi, Christopher Brinton
arXiv Machine Learning
Oct 23

Fine-Grained Analysis of Catastrophic Forgetting in Continual Learning via Algorithmic Stability

The paper introduces an algorithmic stability framework to analyze catastrophic forgetting in continual learning using SGD, without assuming a specific model architecture. It decomposes forgetting into intra‑task and cross‑task generalization gaps plus empirical forgetting, and derives bounds for different learning‑rate schedules. Experiments on Split CIFAR‑100 and Split MiniImageNet illustrate the theoretical insights.

By Guodong Zheng, Yan Sun, Peng Wang, Enneng Yang, Jiafei Lyu, Xiaochun Cao, Dacheng Tao, Li Shen
arXiv AI
Jul 21

First-Order Predictable but Pairwise Fragile: Local Task Adaptation in Trained Transformers

arXiv:2607. 16821v1 Announce Type: cross Abstract: Task arithmetic, sequential fine-tuning, activation steering, and first-order random search all operate through relatively small perturbations around an already trained checkpoint, and they rely on different local approximations: individual perturbations should be first-order predictable, task updates should compose with controlled interference, useful tangent structure should be stable and possible to estimate, and weight edits should have counterparts in representation space.

By Irina Piontkovskaia, Sergey Nikolenko
arXiv Machine Learning
Sep 22

A Shared Learning Rate Is Not a Neutral Control in Selective On-Policy Distillation

The paper investigates selective on‑policy distillation, where a student model is trained only on token positions chosen by a selector. It demonstrates that the commonly used shared learning rate is not neutral: performance varies significantly with the learning rate for different selectors, leading to inconsistent comparisons. The authors attribute this selector‑rate entanglement to the selection process itself and recommend reporting the full arm‑by‑rate matrix for fair evaluation.

By Chencheng Zhu