Diagnostic Analysis for Large Language Model Reasoning

Xinyu Liu, Dongqi Fu, Jun Wu


Abstract
Reasoning structures (e.g., chains and graphs) are increasingly used for probabilistic inference, factuality verification, and uncertainty estimation, but their structural reliability is rarely evaluated directly. We test whether this reliability holds through a proposed two-stage diagnostic evaluation in open-ended multi-hop QA. Stage 1 tests different capabilities required to construct reasoning graphs, showing that graph reliability varies with topology, prompt design, and model family. Stage 2 uses uncertainty estimation as a downstream test case. Generated-edge experiments show that graph-based computation is sensitive to upstream graph errors, with performance dropping relative to the gold-graph setting. Gold-graph experiments further show that graph structure provides little benefit when used only as prompt context, but improves the separation of correct from incorrect answers by confidence score and enables node-level diagnostics.
Anthology ID:
2026.emnlp-main.769
Volume:
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
EMNLP
SIG:
SIGDAT
Publisher:
Association for Computational Linguistics
Note:
Pages:
17842–17867
Language:
URL:
https://aclanthology.org/2026.emnlp-main.769/
DOI:
Bibkey:
Cite (ACL):
Xinyu Liu, Dongqi Fu, and Jun Wu. 2026. Diagnostic Analysis for Large Language Model Reasoning. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 17842–17867, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Diagnostic Analysis for Large Language Model Reasoning (Liu et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.769.pdf