VERGE: Verification-Enhanced Generation of Multi-Hop Evaluation Datasets for Task-Specific RAG

Kyosuke Morita


Abstract
Evaluating retrieval-augmented generation (RAG) on custom knowledge bases requires task-specific benchmarks of multi-chunk evidence synthesis, yet most existing generation pipelines apply quality control only after the full question set has been solved. We present VERGE, which moves quality control inside the generation loop: a verification agent targets, per item and without an external solver pass, an operational multi-chunk criterion and a QA-integrity criterion, refining items that fail and discarding those it cannot repair. From 11,052 candidates across six domains, VERGE yields 2,854 verified multiple-choice items targeting aggregation- and comparison-style synthesis over topically coherent evidence. We contribute a method-agnostic validation protocol — exhaustive strict-subset ablation, chunk-removal ablation, format-unconfounded open-ended re-evaluation, and inter-chunk-similarity stratification — and use it to localise where the multi-chunk dependence holds. On a stratified sample (n = 250), 69.8% of items not answerable closed-book cannot be answered from any strict subset of their supporting chunks (strict-necessity violation rate 15.2%). A human annotation study finds the verifier reliable (Cohen’s 𝜅 = 0.903) and VERGE items higher in QA integrity and distractor quality than the closest prior method (p < 0.001).
Anthology ID:
2026.aacl-long.139
Volume:
Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
November
Year:
2026
Address:
Hengqin, China
Editors:
Yue Zhang, Ruifeng Xu, Ayu Purwarianti, Tong Rong, Jun Suzuki
Venues:
AACL | IJCNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
3036–3062
Language:
URL:
https://aclanthology.org/2026.aacl-long.139/
DOI:
Bibkey:
Cite (ACL):
Kyosuke Morita. 2026. VERGE: Verification-Enhanced Generation of Multi-Hop Evaluation Datasets for Task-Specific RAG. In Proceedings of the 15th International Joint Conference on Natural Language Processing and the 5th Conference of the Asia-Pacific Chapter of the Association for Computational Linguistics (Volume 1: Long Papers), pages 3036–3062, Hengqin, China. Association for Computational Linguistics.
Cite (Informal):
VERGE: Verification-Enhanced Generation of Multi-Hop Evaluation Datasets for Task-Specific RAG (Morita, AACL-IJCNLP 2026)
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PDF:
https://aclanthology.org/2026.aacl-long.139.pdf