arXiv Machine Learning

Beyond State Consistency: Behavior Consistency in Text-Based World Models

The paper introduces a new training paradigm for text-based world models that prioritizes behavior consistency over traditional state consistency metrics. It proposes the Behavior Consistency Reward (BehR), a step-level metric that evaluates how the likelihood of a logged next action changes between real and predicted states using a frozen Reference Agent. Experiments on WebShop and TextWorld demonstrate that BehR-based training improves long-term alignment, reduces false positives in offline evaluation, and yields modest gains in lookahead planning while maintaining or enhancing single-step prediction quality.

arXiv AI
5d ago

CoMAP: Co-Evolving World Models and Agent Policies for LLM Agents

CoMAP introduces a framework that jointly evolves textual world models and agent policies through a closed‑loop interaction. At each decision step the world model forecasts future state feedback for candidate actions, while the agent reflects on the reliability of this feedback to refine its action. The resulting on‑policy trajectories are used to self‑distill and update the world model, improving prediction accuracy and long‑horizon decision‑making across embodied planning, web navigation, and tool‑use benchmarks.

By Youwei Liu, Jian Wang, Hanlin Wang, Wenjie Li
arXiv AI
6d ago

Discriminative World Models for Web Agents

The paper introduces Discriminative World Models for Web Agents, proposing a predicted-state matching objective that trains world models to produce representations that can distinguish the true resulting state from those of alternative actions. Using a branching dataset from WebArena Go-Browse, the authors demonstrate that this approach outperforms traditional supervised next-state prediction on a held‑out benchmark and improves action ranking on WebPRMBench. Additionally, employing the discriminative world model for test‑time action selection boosts end‑to‑end task success on WebArena‑Lite.

By Kelvin Li, Dhruv Pendharkar, Anish Pahilajani, Chuyi Shang, Leon Oks, Leonid Karlinsky, Rogerio Feris, Trevor Darrell, Roei Herzig
arXiv AI
Jun 2

Policy and World Modeling Co-Training for Language Agents

arXiv:2606. 02388v1 Announce Type: cross Abstract: Reinforcement learning (RL) improves large language model (LLM) agents by teaching them which actions lead to high rewards, but provides little supervision on what those actions do to the environment.

By Ning Lu, Baijiong Lin, Shengcai Liu, Jiahao Wu, Haoze Lv, Yanbin Wei, Lingting Zhu, Shengju Qian, Xin Wang, Ying-Cong Chen, Qi Wang, Ke Tang
arXiv AI
5d ago

Imagine-then-Plan: Agent Learning from Adaptive Lookahead with World Models

The paper introduces Imagine-then-Plan (ITP), a framework that lets agents learn by interacting with a learned world model to generate multi-step imagined trajectories. ITP features an adaptive lookahead mechanism that balances ultimate goals with task progress, producing richer signals about future outcomes. Experiments on various benchmarks show that ITP outperforms existing baselines, and analyses suggest the adaptive lookahead improves reasoning for complex tasks.

By Youwei Liu, Jian Wang, Hanlin Wang, Beichen Guo, Wenjie Li