Graph Serializations for Reasoning LLMs: A Study Across Knowledge Extraction and Structural Reasoning

Julien Yu, Mihaela Bornea, Avi Sil, Katrin Kirchhoff


Abstract
The way a knowledge graph is serialized as text for inclusion into LLM context can substantially affect downstream LLM performance, with prior work reporting tens of percentage points variations across formats. However, existing studies consider only a limited set of representations and predate frontier reasoning models, which now offer stronger reasoning, instruction-following, and long-context capabilities. We evaluate 15 graph representation formats across nine frontier LLM configurations on ontology-based knowledge extraction and structural graph reasoning tasks. While knowledge extraction is relatively insensitive to different serialization formats, the choice of the optimal format for structural reasoning tasks significantly affects accuracy. We demonstrate that the optimal representation choice depends on model, query, and task and propose to approach graph serialization as a dynamic orchestration decision.
Anthology ID:
2026.findings-emnlp.558
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
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SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
11779–11794
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URL:
https://aclanthology.org/2026.findings-emnlp.558/
DOI:
Bibkey:
Cite (ACL):
Julien Yu, Mihaela Bornea, Avi Sil, and Katrin Kirchhoff. 2026. Graph Serializations for Reasoning LLMs: A Study Across Knowledge Extraction and Structural Reasoning. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 11779–11794, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Graph Serializations for Reasoning LLMs: A Study Across Knowledge Extraction and Structural Reasoning (Yu et al., Findings 2026)
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https://aclanthology.org/2026.findings-emnlp.558.pdf