Omanic: Towards Step-wise Evaluation of Multi-hop Reasoning in Large Language Models

Xiaojie Gu, Sherry T. Tong, Aosong Feng, Sophia Simeng Han, Jinghui Lu +6 more
3/17/2026
cs.CLcs.AIcs.LG

No confident code implementation found for this paper. 2 possible matches can be shown below.

Abstract

Reasoning-focused large language models (LLMs) have advanced in many NLP tasks, yet their evaluation remains challenging: final answers alone do not expose the intermediate reasoning steps, making it difficult to determine whether a model truly reasons correctly and where failures occur, while existing multi-hop QA benchmarks lack step-level annotations for diagnosing reasoning failures. To address this gap, we propose Omanic, an open-domain multi-hop QA resource that provides decomposed sub-questions and intermediate answers as structural annotations for analyzing reasoning processes. It contains 10,296 machine-generated training examples (OmanicSynth) and 967 expert-reviewed human-annotated evaluation examples (OmanicBench). Systematic evaluations show that state-of-the-art LLMs achieve only 73.11% multiple-choice accuracy on OmanicBench, confirming its high difficulty. Stepwise analysis reveals that CoT's performance hinges on factual completeness, with its gains diminishing under knowledge gaps and errors amplifying in later hops. Additionally, supervised fine-tuning on OmanicSynth brings substantial transfer gains (7.41 average points) across six reasoning and math benchmarks, validating the dataset's quality and further supporting the effectiveness of OmanicSynth as supervision for reasoning-capability transfer. We release the data at https://huggingface.co/datasets/li-lab/Omanic and the code at https://github.com/XiaojieGu/Omanic.

View on arXivView PDF

Code Implementations

No confident code match yet

We couldn't find an author-owned or strongly-evidenced community implementation for this paper. 2 weaker matches are hidden by default — verify before relying on them.

No code implementations found yet.

Know of an implementation? Let us know in the comments below!

Cite this paper

@article{gu2026omanic,
  title  = {Omanic: Towards Step-wise Evaluation of Multi-hop Reasoning in Large Language Models},
  author = {Xiaojie Gu and Sherry T. Tong and Aosong Feng and Sophia Simeng Han and Jinghui Lu and Yingjian Chen and Yusuke Iwasawa and Yutaka Matsuo and Chanjun Park and Rex Ying and Irene Li},
  year   = {2026},
  eprint = {2603.16654},
  archivePrefix = {arXiv},
  url    = {http://arxiv.org/abs/2603.16654v1}
}

Add a badge to your README

Shows whether official code is linked for this paper.

Code of Paper badge
[![Code of Paper](https://codeofpaper.com/badge/2603.16654.svg)](https://codeofpaper.com/paper/2603.16654)

Discussion