The Canonical Order Problem: When Large Language Models Are Unreliable Knowledge Bases for Multi-Valued Relations

Timo Pierre Schrader, Annemarie Friedrich, Simon Razniewski, Lukas Lange


Abstract
Large language models (LLMs) are increasingly used as knowledge bases (KBs) due to the vast amount of knowledge they acquire during pre-training. While many works focus on extracting single relational triples, most real-world relations are multi-valued and require generating sets of entities.

In this paper, we investigate how LLMs represent and generate multi-valued relations. We identify the canonical order problem: The probabilistic distributions inside LLMs organize many multi-valued relations according to a canonical ordering (e.g., alphabetical or chronological). Through mechanistic analysis, we show that set generation in LLMs can be thought of in terms of three phases: (1) retrieval of candidate entities, (2) internal sorting, and (3) selection of the next element. As a result, prompts aiming to construct KBs that deviate from this internal canonical ordering lead to a markedly reduced reliability of LLMs when aiming to generate complete sets for multi-valued relations.
Anthology ID:
2026.akbc-1.5
Volume:
Proceedings of the 11th Workshop on Automated Knowledge Base Construction (AKBC 2026)
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Jan-Christoph Kalo, Ndapa Nakashole, Simon Razniewski, Fabian M. Suchanek, Andreas Vlachos, Andrew McCallum
Venues:
AKBC | WS
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
45–55
Language:
URL:
https://aclanthology.org/2026.akbc-1.5/
DOI:
Bibkey:
Cite (ACL):
Timo Pierre Schrader, Annemarie Friedrich, Simon Razniewski, and Lukas Lange. 2026. The Canonical Order Problem: When Large Language Models Are Unreliable Knowledge Bases for Multi-Valued Relations. In Proceedings of the 11th Workshop on Automated Knowledge Base Construction (AKBC 2026), pages 45–55, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
The Canonical Order Problem: When Large Language Models Are Unreliable Knowledge Bases for Multi-Valued Relations (Schrader et al., AKBC 2026)
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PDF:
https://aclanthology.org/2026.akbc-1.5.pdf