IterCOMP: Reasoning-aware Adaptive Prompt Compression for Multi-hop Question Answering

JungMin Yun, YoungBin Kim


Abstract
Multi-hop question answering requires complex reasoning across multiple evidence segments, which often overwhelms retrieval-augmented generation systems with lengthy and noisy contexts, thereby undermining both efficiency and accuracy. While existing prompt compression methods attempt to address this issue, they are typically designed for single-turn queries and fail to capture interdependent reasoning steps. We propose IterCOMP, a unified, training-free prompt compression framework that incorporates multi-hop reasoning within an iterative compression loop. IterCOMP decomposes documents into evidence segments, evaluates question answerability, and generates targeted follow-up questions to iteratively integrate essential evidence, producing a compact, reasoning-oriented prompt. Experiments on MusiQue, 2WikiMultiHopQA, and HotpotQA demonstrate that IterCOMP achieves substantial improvements in Exact Match and F1 scores while reducing the token budget, outperforming existing baselines and exhibiting robustness as reasoning complexity increases.
Anthology ID:
2026.acl-long.1559
Volume:
Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
July
Year:
2026
Address:
San Diego, California, United States
Editors:
Maria Liakata, Viviane P. Moreira, Jiajun Zhang, David Jurgens
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
33827–33840
Language:
URL:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.1559/
DOI:
Bibkey:
Cite (ACL):
JungMin Yun and YoungBin Kim. 2026. IterCOMP: Reasoning-aware Adaptive Prompt Compression for Multi-hop Question Answering. In Proceedings of the 64th Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 33827–33840, San Diego, California, United States. Association for Computational Linguistics.
Cite (Informal):
IterCOMP: Reasoning-aware Adaptive Prompt Compression for Multi-hop Question Answering (Yun & Kim, ACL 2026)
Copy Citation:
PDF:
https://preview.aclanthology.org/ingest-acl/2026.acl-long.1559.pdf
Checklist:
 2026.acl-long.1559.checklist.pdf