Saved in:
Bibliographic Details
Main Authors: Six, Valentin, Panse, Frederik, Fajeau, Mathis, Da Costa, Lancelot, Sharma, Mridul, Amayuelas, Alfonso, Xiao, Tim Z., Hyland, David, Hennig, Philipp, Schölkopf, Bernhard
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2605.13740
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911681702002688
author Six, Valentin
Panse, Frederik
Fajeau, Mathis
Da Costa, Lancelot
Sharma, Mridul
Amayuelas, Alfonso
Xiao, Tim Z.
Hyland, David
Hennig, Philipp
Schölkopf, Bernhard
author_facet Six, Valentin
Panse, Frederik
Fajeau, Mathis
Da Costa, Lancelot
Sharma, Mridul
Amayuelas, Alfonso
Xiao, Tim Z.
Hyland, David
Hennig, Philipp
Schölkopf, Bernhard
contents Whether navigating a building, operating a robot, or playing a game, an agent that acts effectively in an environment must first learn an internal model of how that environment works. Partially-observable Markov decision processes (POMDPs) provide a flexible modeling class for such internal world models, but learning them from observation-action trajectories alone is challenging and typically requires extensive environment interaction. We ask whether language-model priors can reduce costly interaction by leveraging prior knowledge, and introduce \emph{Pinductor} (POMDP-inductor): an LLM proposes candidate POMDP models from a few observation-action trajectories and iteratively refines them to optimize a belief-based likelihood score. Despite using strictly less information, \emph{Pinductor} matches the performance and sample efficiency of LLM-based POMDP learning methods that assume privileged access to the hidden state, while significantly surpassing the sample efficiency of tabular POMDP baselines. Further results show that performance scales with LLM capability and degrades gracefully as semantic information about the environment is withheld. Together, these results position language-model priors as a practical tool for sample-efficient world-model learning under partial observability, and a step toward generalist agents in real-world environments. Code is available at https://github.com/atomresearch/pinductor.
format Preprint
id arxiv_https___arxiv_org_abs_2605_13740
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Learning POMDP World Models from Observations with Language-Model Priors
Six, Valentin
Panse, Frederik
Fajeau, Mathis
Da Costa, Lancelot
Sharma, Mridul
Amayuelas, Alfonso
Xiao, Tim Z.
Hyland, David
Hennig, Philipp
Schölkopf, Bernhard
Machine Learning
Whether navigating a building, operating a robot, or playing a game, an agent that acts effectively in an environment must first learn an internal model of how that environment works. Partially-observable Markov decision processes (POMDPs) provide a flexible modeling class for such internal world models, but learning them from observation-action trajectories alone is challenging and typically requires extensive environment interaction. We ask whether language-model priors can reduce costly interaction by leveraging prior knowledge, and introduce \emph{Pinductor} (POMDP-inductor): an LLM proposes candidate POMDP models from a few observation-action trajectories and iteratively refines them to optimize a belief-based likelihood score. Despite using strictly less information, \emph{Pinductor} matches the performance and sample efficiency of LLM-based POMDP learning methods that assume privileged access to the hidden state, while significantly surpassing the sample efficiency of tabular POMDP baselines. Further results show that performance scales with LLM capability and degrades gracefully as semantic information about the environment is withheld. Together, these results position language-model priors as a practical tool for sample-efficient world-model learning under partial observability, and a step toward generalist agents in real-world environments. Code is available at https://github.com/atomresearch/pinductor.
title Learning POMDP World Models from Observations with Language-Model Priors
topic Machine Learning
url https://arxiv.org/abs/2605.13740