Saved in:
Bibliographic Details
Main Authors: Vossebeld, Floris, Wang, Shenghui
Format: Preprint
Published: 2025
Subjects:
Online Access:https://arxiv.org/abs/2511.11770
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866908654434779136
author Vossebeld, Floris
Wang, Shenghui
author_facet Vossebeld, Floris
Wang, Shenghui
contents Generating complex, logically-sound SPARQL queries for multi-hop questions remains a critical bottleneck for Knowledge Graph Question Answering, as the brittle nature of one-shot generation by Large Language Models (LLMs) hinders reliable interaction with structured data. Current methods lack the adaptive policies needed to dynamically debug queries based on real-time execution feedback. This paper introduces a novel agentic framework where an LLM learns a resilient policy for the sequential process of iterative SPARQL construction. We show that a compact 3B-parameter model, trained exclusively via outcome-driven Reinforcement Learning (GRPO) without supervised fine-tuning, can learn effective policies for this task, discovering how to systematically recover from execution errors and refine its queries toward a correct answer. On a curated, executable single-answer subset of LC-QuAD 2.0, our agent achieves 49.7\% accuracy post-entity-linking, a significant 17.5 percentage point improvement over the strongest iterative zero-shot baseline. Further analysis reveals that while the agent's capability is driven by RL, its performance is enhanced by an explicit deliberative reasoning step that acts as a cognitive scaffold to improve policy precision. This work presents a generalizable blueprint for teaching agents to master formal, symbolic tools through interaction, bridging the gap between probabilistic LLMs and the structured world of Knowledge Graphs.
format Preprint
id arxiv_https___arxiv_org_abs_2511_11770
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Learning to Refine: An Agentic RL Approach for Iterative SPARQL Query Construction
Vossebeld, Floris
Wang, Shenghui
Artificial Intelligence
Machine Learning
68P20, 68T42
H.3.3; I.2.4
Generating complex, logically-sound SPARQL queries for multi-hop questions remains a critical bottleneck for Knowledge Graph Question Answering, as the brittle nature of one-shot generation by Large Language Models (LLMs) hinders reliable interaction with structured data. Current methods lack the adaptive policies needed to dynamically debug queries based on real-time execution feedback. This paper introduces a novel agentic framework where an LLM learns a resilient policy for the sequential process of iterative SPARQL construction. We show that a compact 3B-parameter model, trained exclusively via outcome-driven Reinforcement Learning (GRPO) without supervised fine-tuning, can learn effective policies for this task, discovering how to systematically recover from execution errors and refine its queries toward a correct answer. On a curated, executable single-answer subset of LC-QuAD 2.0, our agent achieves 49.7\% accuracy post-entity-linking, a significant 17.5 percentage point improvement over the strongest iterative zero-shot baseline. Further analysis reveals that while the agent's capability is driven by RL, its performance is enhanced by an explicit deliberative reasoning step that acts as a cognitive scaffold to improve policy precision. This work presents a generalizable blueprint for teaching agents to master formal, symbolic tools through interaction, bridging the gap between probabilistic LLMs and the structured world of Knowledge Graphs.
title Learning to Refine: An Agentic RL Approach for Iterative SPARQL Query Construction
topic Artificial Intelligence
Machine Learning
68P20, 68T42
H.3.3; I.2.4
url https://arxiv.org/abs/2511.11770