Case-Based Decision-Theoretic Decoding with Quality Memories

Hiroyuki Deguchi, Masaaki Nagata


Abstract
Minimum Bayes risk (MBR) decoding is a decision rule of text generation, which selects the hypothesis that maximizes the expected utility and robustly generates higher-quality texts than maximum a posteriori (MAP) decoding.However, it depends on sample texts drawn from the text generation model; thus, it is difficult to find a hypothesis that correctly captures the knowledge or information of out-of-domain.To tackle this issue, we propose case-based decision-theoretic (CBDT) decoding, another method to estimate the expected utility using examples of domain data.CBDT decoding not only generates higher-quality texts than MAP decoding, but also the combination of MBR and CBDT decoding outperformed MBR decoding in seven domain De–En and JaEn translation tasks and image captioning tasks on MSCOCO and nocaps datasets.
Anthology ID:
2025.emnlp-main.1710
Volume:
Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing
Month:
November
Year:
2025
Address:
Suzhou, China
Editors:
Christos Christodoulopoulos, Tanmoy Chakraborty, Carolyn Rose, Violet Peng
Venue:
EMNLP
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
33679–33694
Language:
URL:
https://preview.aclanthology.org/name-variant-enfa-fane/2025.emnlp-main.1710/
DOI:
10.18653/v1/2025.emnlp-main.1710
Bibkey:
Cite (ACL):
Hiroyuki Deguchi and Masaaki Nagata. 2025. Case-Based Decision-Theoretic Decoding with Quality Memories. In Proceedings of the 2025 Conference on Empirical Methods in Natural Language Processing, pages 33679–33694, Suzhou, China. Association for Computational Linguistics.
Cite (Informal):
Case-Based Decision-Theoretic Decoding with Quality Memories (Deguchi & Nagata, EMNLP 2025)
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