arXiv AI

Efficient Exploration Is Enough

arXiv Machine Learning
Oct 3

When Do Intrinsic Rewards Lead to Exploration?

The paper investigates when intrinsic rewards effectively drive exploration in reinforcement learning. It introduces a formal criterion that evaluates policies based on the counterfactual information they acquire, comparing how well their histories can replace experience from alternative policies. Using a simple environment, the authors show that common intrinsic reward objectives—count-based, prediction-error, empowerment, and information-gain—can lead to Pareto-suboptimal exploration under this criterion, and they propose conditions and a new objective that better align with optimal exploration.

By Scott W. Viteri (Stanford University), Laura Gomezjurado Gonzalez (Stanford University), Clark Barrett (Stanford University)
arXiv AI
Oct 1

PhantomEnvironments: Training LLM Agents in Fictional Worlds

PhantomEnvironments is a framework that trains large language model agents in synthetic, rule‑generated fictional worlds. By creating multi‑turn reinforcement learning environments where agents search templated articles to answer multi‑hop questions, the approach eliminates the need for costly human data or hallucinated LLM‑generated settings. Agents trained in these zero‑cost, purely rule‑based worlds transfer effectively to real‑world multi‑hop search benchmarks, often surpassing models trained on real data, and demonstrate scalable search behavior that grows linearly with question difficulty.

By Anmol Kabra, Swathi Saravana Selvam, Albert Gong, Chao Wan, Christian Belardi, Dongyoung Go, Katie Z. Luo, Kilian Q. Weinberger
arXiv Machine Learning
1d ago

Exploration via Exploitation: The Blessing of Reward Diversity in Personalized Federated RL

The paper introduces two algorithms for personalized federated reinforcement learning: PF-UCBVI, which achieves optimal linear speedup by separating shared dynamics from individual goals, and PF-EFVI, a greedy method that uses reward diversity to guarantee state-action coverage without explicit exploration bonuses. The authors prove that PF-EFVI attains logarithmic regret under sufficient reward diversity, showing that disagreement among agents can shift the exploration burden from temporal to spatial aspects. This demonstrates that heterogeneous rewards can be leveraged as a structural asset to facilitate efficient collective learning.

By Jiin Woo, Gauri Joshi, Yuejie Chi