arXiv AI

Events, Not Pixels: Where World Models Get the Return Wrong

The paper investigates why world models used for planning can misjudge returns despite producing visually accurate rollouts. By replacing imagined transitions with real ones at key event steps—where rewards are earned or episodes end—the authors show that correcting these few transitions eliminates about 70% of return errors, outperforming corrections based on high visual error metrics. Across 44 Atari-100k model–collection pairs, event-based patches significantly improve plan ranking, revealing a structured pattern of remaining errors that can guide further repairs.

arXiv Machine Learning
Sep 1

The Intervention Gap in Latent World Models

The paper introduces the concept of intervention fidelity in latent world models, measuring whether a model’s open‑loop transitions align with actual environment interventions. Experiments on TD‑MPC2, Cheetah, and DreamerV3 show that high reward fit does not guarantee fidelity, and that self‑supervised models can outperform task‑anchored ones in preserving intervention effects. The authors propose a capture‑gated audit to localize failures and argue that fidelity must be directly audited on the model’s native interface.

By Donna Vakalis
arXiv Machine Learning
Oct 9

Reliability-Aware Future Conditioning for Temporally Robust Robot Manipulation

The paper introduces Reliability‑Aware Future Conditioning (RAFC), a method that dynamically estimates how much to trust a generated future video clip and selects the most appropriate temporal hypothesis for robot manipulation tasks. By treating temporal misalignment as a control problem rather than a generation problem, RAFC improves success rates on the CALVIN benchmark and a Franka robot under various timing mismatches, outperforming static and uniform‑averaging baselines. The approach builds on Future‑Experience Conditioning (FEC) and learns solely from task reward without explicit alignment supervision.

By Mohammad Khoshnazar, Mohammad Dehghani Tezerjani, Zhiyuan Gao, Deyuan Qu, Max Gandyra, Yanxiang Zhan, Mehreen Naeem, Andrew Melnik, Jeroen Schafer, Qing Yang, Michael Beetz
arXiv Machine Learning
Oct 15

One-Step Prediction Fidelity Is a Poor Proxy for Planning Performance in JEPA World Models

The paper challenges the common practice of selecting latent world models based on one‑step prediction loss, arguing that this metric poorly predicts planning performance. Using a frozen‑decoder protocol, the authors decompose one‑step error into encoder‑inherent and predictor‑added components and evaluate goal‑conditioned planning across three continuous‑control environments. Their experiments show that improvements in one‑step fidelity do not correlate with planning success, with correlation coefficients near zero and inconsistent exchange rates across tasks.

By Joshua Cheung, Zhang He
arXiv Machine Learning
Oct 2

When Instructions Retrieve Trajectories: Diagnosing and Mitigating Generalization Failures in VLA Models

The paper investigates a specific failure mode in vision‑language‑action models, termed instruction‑action binding, where models respond to language and vision separately but fail to combine them to select the correct action under counterfactual changes. Through behavioral analyses of fine‑tuned policies, the authors show that failed rollouts often preserve source behavior or switch to other demonstrated tasks, indicating that language is not ignored but mis‑bound. They propose Equivariant Counterfactual Training (ECT), which supplies counterfactual demonstrations and a paired loss to enforce correct action selection, achieving significant performance gains across simulated and real‑world benchmarks.

By Hung-Jen Chen, Yu-Hsun Hou, Yan-Hong Chen, Yan-Fu Chen, Binghua Cai, Min Sun, Chun-Yi Lee
arXiv AI
Oct 1

ATM: Why Latent World Models Can Fail to Plan

The paper investigates why latent world models, despite accurate latent predictions, can perform poorly in downstream planning. It introduces the concept of action-identifiability and formalizes it via Bayes inverse risk, showing that self-decodable predicted transitions may encode domain‑specific action relationships that do not transfer to real environments. Using the Action‑Consistency Transfer Matrix (ATM), the authors demonstrate that true‑transition action‑identifiability correlates strongly with planning success across several benchmarks, and that the ATM can diagnose cross‑domain inconsistencies and aid lightweight model screening.

By Jiaheng Chen, Tinghe Zhang, Yucheng Xiao, Xinyong Cai, Lan Yu, Juncheng Bu, Jiaxing Li, Yunlong Wang
arXiv AI
Sep 24

DreamAvoid: Critical-Phase Test-Time Dreaming to Avoid Failures in VLA Policies

DreamAvoid introduces a test‑time dreaming framework for Vision‑Language‑Action models to anticipate and avoid failures during critical manipulation phases. It uses a Dream Trigger to detect critical phases, samples candidate action chunks via an Action Proposer, and evaluates short‑horizon futures with a Dream Evaluator trained on success, failure, and boundary data. Experiments on real‑world and simulated tasks show DreamAvoid improves task success rates, achieving 72.5% success versus 48.8% for the base policy and 54.4% for GPC‑RANK.

By Xianzhe Fan, Yuxiang Lu, Shenyuan Gao, Xiaoyang Wu, Ruihua Han, Manling Li, Hengshuang Zhao
arXiv AI
Oct 16

ValueFormer: Stage-Aware Value Labels for Online Failure Detection and VLA Post-Training

ValueFormer introduces stage‑aware, continuous value labels for online failure detection in vision‑language‑action policies. The method uses a 3.5 M‑parameter causal transformer over a frozen DINOv3 backbone to emit per‑frame smooth Monte‑Carlo values for advantage estimation and sharp binary signals for mistake detection. In experiments, reusing teleoperation intervention flags boosts detection AP from 0.38 to 0.82 and flags 95 % of mistakes early; on a bimanual sandwich station, per‑frame post‑training weighting raises task completion from 70 % to 85 % and eliminates a repeat‑pick failure mode.

By Inkyu Sa, Konstantin Stulov, Rajat Bhageria