Beyond Output Correctness: Benchmarking and Evaluating Large Language Model Reasoning in Coding Tasks

Yuangang Li, Justin Tian Jin Chen, Ethan Yu, David Hong, Iftekhar Ahmed


Abstract
Large language models (LLMs) increasingly rely on explicit reasoning to solve coding tasks, yet evaluating the quality of this reasoning remains challenging. Existing reasoning evaluators are not designed for coding, and current benchmarks focus primarily on code generation, leaving other coding tasks largely unexplored. We introduce CodeRQ-Bench, the first benchmark for evaluating LLM reasoning quality across three coding task categories: generation, summarization, and classification. Using this benchmark, we analyze 1,069 mismatch cases from existing evaluators, identify five recurring limitations, and derive four design insights for reasoning evaluation in coding tasks. Guided by these insights, we propose VERA, a two-stage evaluator that combines evidence-grounded verification with ambiguity-aware score correction. Experiments on CodeRQ-Bench show that VERA consistently outperforms strong baselines across four datasets, improving AUCROC by up to 0.26 and AUPRC by up to 0.21. We release CodeRQ-Bench at https://github.com/MrLYG/CodeRQ-Bench, supporting future investigations.
Anthology ID:
2026.emnlp-main.680
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:
15666–15689
Language:
URL:
https://aclanthology.org/2026.emnlp-main.680/
DOI:
Bibkey:
Cite (ACL):
Yuangang Li, Justin Tian Jin Chen, Ethan Yu, David Hong, and Iftekhar Ahmed. 2026. Beyond Output Correctness: Benchmarking and Evaluating Large Language Model Reasoning in Coding Tasks. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 15666–15689, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Beyond Output Correctness: Benchmarking and Evaluating Large Language Model Reasoning in Coding Tasks (Li et al., EMNLP 2026)
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PDF:
https://aclanthology.org/2026.emnlp-main.680.pdf