Adaptive Reasoning for Efficient Generative Retrieval

Yingchen Zhang, Ruqing Zhang, Jiafeng Guo, Wenjun Peng, Sen Li, Fuyu Lv, Xueqi Cheng


Abstract
Generative retrieval (GR) retrieves documents by directly generating document identifiers (DocIDs) from queries using a sequence-to-sequence model. Recent reasoning-enhanced GR methods improve retrieval effectiveness by generating intermediate reasoning before DocID decoding. However, they typically apply reasoning uniformly to all queries, even though many queries can already be handled effectively through direct DocID decoding. This introduces unnecessary token generation and retrieval latency when reasoning provides little additional benefit. In this work, we propose Generative Retrieval with Adaptive Reasoning (GEAR), a retrieval framework that dynamically allocates reasoning computation based on query-specific needs. Instead of treating reasoning as a fixed pre-retrieval procedure, GEAR learns when to reason, what retrieval-oriented context to generate, and when to transition from free-form generation to constrained DocID decoding. This adaptive behavior is implemented through a learnable retrieval transition policy optimized jointly for retrieval quality and reasoning cost. Experiments on NQ, MS MARCO, and TREC DL 2022 show that GEAR maintains retrieval effectiveness comparable to strong reasoning-enhanced GR methods while substantially reducing reasoning overhead, triggering non-trivial reasoning for only 37.1% of queries and reducing both generated tokens and retrieval latency.
Anthology ID:
2026.emnlp-main.2224
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:
50634–50647
Language:
URL:
https://aclanthology.org/2026.emnlp-main.2224/
DOI:
Bibkey:
Cite (ACL):
Yingchen Zhang, Ruqing Zhang, Jiafeng Guo, Wenjun Peng, Sen Li, Fuyu Lv, and Xueqi Cheng. 2026. Adaptive Reasoning for Efficient Generative Retrieval. In Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing, pages 50634–50647, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
Adaptive Reasoning for Efficient Generative Retrieval (Zhang et al., EMNLP 2026)
Copy Citation:
PDF:
https://aclanthology.org/2026.emnlp-main.2224.pdf