arXiv Machine Learning
Sep 1

Discrete Compositional Generation via General Soft Operators and Robust Reinforcement Learning

arXiv:2506.17007v3 Announce Type: replace Abstract: A major bottleneck in scientific discovery consists of narrowing an exponentially large set of objects, such as proteins or molecules, to a small s...

By Marco Jiralerspong, Esther Derman, Danilo Vucetic, Esmeralda S. Whitammer, Bilun Sun, Tianyu Zhang, Pierre-Luc Bacon, Gauthier Gidel
arXiv Machine Learning
Oct 5

Understanding Enrichment in Reinforcement Learning

The paper investigates how enrichment—adding intermediate guidance to sparse rewards in reinforcement learning—affects policy-gradient updates. It shows that omitting or truncating importance-weight corrections implicitly reweights rewards, and decomposes the resulting gradient error into scale, rotation, and variance components. The authors propose a sequential Monte Carlo weight correction that mitigates variance growth, and apply their analysis to a fine-tuned Qwen3-1.7B model on OpenMathReasoning, illustrating how enrichment helps prevent collapse in sparse domains.

By Jinwoo Kim, Shraddha Barke
arXiv Machine Learning
Jun 25

ExTra: Exploratory Trajectory Optimization for Language Model Reinforcement Learning

arXiv:2606. 24994v1 Announce Type: new Abstract: Reinforcement Learning with Verifiable Rewards (RLVR) for language-model reasoning can fail at both extremes of task difficulty: easy prompts often produce all-correct, low-diversity rollout groups with little gradient signal, while hard prompts can produce all-incorrect groups with no positive reward.

By Wenyang Hu, Junxiang Jia, Zhen Shu, Daniel Dahlmeier, See-Kiong Ng, Bryan Kian Hsiang Low