Knowledge Graphs are Implicit Reward Models: Path-Derived Signals Enable Compositional Reasoning

Fuente: arXiv
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Main Authors: Kansal, Yuval, Jha, Niraj K.
Format: Preprint
Published: 2026
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author Kansal, Yuval
Jha, Niraj K.
author_facet Kansal, Yuval
Jha, Niraj K.
contents Large language models have achieved near-expert performance in structured reasoning domains like mathematics and programming, yet their ability to perform compositional multi-hop reasoning in specialized scientific fields remains limited. We propose a bottom-up learning paradigm in which models are grounded in axiomatic domain facts and compose them to solve complex, unseen tasks. To this end, we present a post-training pipeline, based on a combination of supervised fine-tuning and reinforcement learning (RL), in which knowledge graphs act as implicit reward models. By deriving novel reward signals from knowledge graph paths, we provide verifiable, scalable, and grounded supervision that encourages models to compose intermediate axioms rather than optimize only final answers during RL. We validate this approach in the medical domain, training a 14B model on short-hop reasoning paths (1-3 hops) and evaluating its zero-shot generalization to complex multi-hop queries (4-5 hops). Our experiments show that path-derived rewards act as a "compositional bridge", enabling our model to significantly outperform much larger models and frontier systems like GPT-5.2 and Gemini 3 Pro, on the most difficult reasoning tasks. Furthermore, we demonstrate the robustness of our approach to adversarial perturbations against option-shuffling stress tests. This work suggests that grounding the reasoning process in structured knowledge is a scalable and efficient path toward intelligent reasoning. Our code is publicly available at: https://github.com/jha-lab/kg-implicit-reward-compositional-rl/.
format Preprint
id arxiv_https___arxiv_org_abs_2601_15160
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Knowledge Graphs are Implicit Reward Models: Path-Derived Signals Enable Compositional Reasoning
Kansal, Yuval
Jha, Niraj K.
Artificial Intelligence
Computation and Language
Large language models have achieved near-expert performance in structured reasoning domains like mathematics and programming, yet their ability to perform compositional multi-hop reasoning in specialized scientific fields remains limited. We propose a bottom-up learning paradigm in which models are grounded in axiomatic domain facts and compose them to solve complex, unseen tasks. To this end, we present a post-training pipeline, based on a combination of supervised fine-tuning and reinforcement learning (RL), in which knowledge graphs act as implicit reward models. By deriving novel reward signals from knowledge graph paths, we provide verifiable, scalable, and grounded supervision that encourages models to compose intermediate axioms rather than optimize only final answers during RL. We validate this approach in the medical domain, training a 14B model on short-hop reasoning paths (1-3 hops) and evaluating its zero-shot generalization to complex multi-hop queries (4-5 hops). Our experiments show that path-derived rewards act as a "compositional bridge", enabling our model to significantly outperform much larger models and frontier systems like GPT-5.2 and Gemini 3 Pro, on the most difficult reasoning tasks. Furthermore, we demonstrate the robustness of our approach to adversarial perturbations against option-shuffling stress tests. This work suggests that grounding the reasoning process in structured knowledge is a scalable and efficient path toward intelligent reasoning. Our code is publicly available at: https://github.com/jha-lab/kg-implicit-reward-compositional-rl/.
title Knowledge Graphs are Implicit Reward Models: Path-Derived Signals Enable Compositional Reasoning
topic Artificial Intelligence
Computation and Language
url https://arxiv.org/abs/2601.15160