arXiv Machine Learning

Trust Guided Decision Transformer

The paper introduces Trust Guided Decision Transformer (TGDT), a method that mitigates performance degradation in Decision Transformers during long rollouts by monitoring the model’s next‑state prediction error. TGDT evaluates multiple recent context suffixes, filters out those whose prediction error exceeds a calibrated threshold, and then selects the highest‑value action from the remaining trusted suffixes using a frozen critic. Experiments on D4RL navigation and locomotion tasks demonstrate that TGDT reduces persistent high‑error runs and improves returns compared to vanilla Decision Transformer and other context‑control baselines.

arXiv Machine Learning
Sep 21

Adaptive Rollout Truncation Based on Epistemic Uncertainty for Efficient Offline World Model Training

The paper introduces an adaptive rollout truncation method for offline world model training that uses epistemic uncertainty to decide when to stop autoregressive rollouts. By calibrating a threshold during a warm‑up phase, the approach replaces fixed‑horizon rollouts with uncertainty‑driven truncation, evaluated with ensemble and Monte Carlo dropout estimators. Experiments on ANYmal‑D and ANT demonstrate that this strategy matches or surpasses fixed‑horizon training while reducing cumulative rollout steps by about 72%.

By Nikodem Sebastian Zymla, Laurin Thiele, Johannes Pitz
arXiv AI
Aug 5

ValueFormer: A Causal Transformer Value Function with Stage-Aware Labels for Semi-Autonomous Vision-Language-Action Policies

arXiv:2608. 02958v1 Announce Type: cross Abstract: Vision-Language-Action (VLA) policies trained by behavior cloning fail silently: from the action stream alone, a collapsing rollout looks much like one making clean progress, because imitation supplies no notion of progress.

By Inkyu Sa, Konstantin Stulov, Rajat Bhageria
arXiv Machine Learning
Sep 1

World Model Control by Trajectory Reachability Metrics

arXiv:2605.22164v2 Announce Type: replace Abstract: Latent world models can learn representations that contain information needed for control, while the downstream controller may still rank candidate...

By Liangyu Li, Shengzhi Wang, Libin Qiu, Mingliang Xiong, Qingwen Liu
arXiv Machine Learning
Sep 25

Certified Predictive Value-of-Advice Gating for Cost-Aware Language-Model Guidance in Reinforcement Learning

The paper proposes a method for selectively querying language‑model advice in reinforcement learning by predicting the value of potential responses and only querying when the expected benefit outweighs the cost. It introduces a certified, response‑contingent metareasoning framework that guarantees near‑optimal advice usage under certain assumptions, and demonstrates that a calibrated controller with Qwen2.5 advisors can improve task performance while drastically reducing the number of advice calls on the BabyAI benchmark.

By Ibne Farabi Shihab, Md Najmus Swaqeeb, Abu Sa-Adat Mohamed Moon-Im Al Ahsan
arXiv AI
Jul 2

The State-Prediction Separation Hypothesis

arXiv:2607. 01218v1 Announce Type: cross Abstract: Transformers use the same forward computation stream to both predict the next token and store useful state for future token predictions.

By Giovanni Monea, Nathan Godey, Kiant\'e Brantley, Yoav Artzi
arXiv AI
4d ago

Measuring the Stability Assumption Behind Action Chunking

The paper investigates how small action errors evolve when using action chunking in behavioural cloning. By injecting errors at each state and observing their growth under open‑loop (no replanning) and closed‑loop (replanning) regimes, the authors classify states as contracting, expanding, or unresolved. Across twelve manipulation tasks, they find that stable states are rare, error amplification is common, and that short‑horizon fitting can overestimate long‑horizon propagation. Predictors trained on camera and proprioceptive data can recover open‑loop stability but only partially capture closed‑loop dynamics, indicating that standard imitation learning does not reliably produce policies that contract errors when perturbed.

By Aryan Goyal