Lightweight reranking for language model generations

Siddhartha Jain, Xiaofei Ma, Anoop Deoras, Bing Xiang


Abstract
Large Language Models (LLMs) can exhibit considerable variation in the quality of their sampled outputs. Reranking and selecting the best generation from the sampled set is a popular way of obtaining strong gains in generation quality. In this paper, we present a novel approach for reranking LLM generations. Unlike other techniques that might involve additional inferences or training a specialized reranker, our approach relies on easy to compute pairwise statistics between the generations that have minimal compute overhead. We show that our approach can be formalized as an extension of self-consistency and analyze its performance in that framework, theoretically as well as via simulations. We show strong improvements for selecting the best k generations for code generation tasks as well as robust improvements for the best generation for the tasks of autoformalization, summarization, and translation. While our approach only assumes black-box access to LLMs, we show that additional access to token probabilities can improve performance even further.
Anthology ID:
2024.acl-long.376
Volume:
Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers)
Month:
August
Year:
2024
Address:
Bangkok, Thailand
Editors:
Lun-Wei Ku, Andre Martins, Vivek Srikumar
Venue:
ACL
SIG:
Publisher:
Association for Computational Linguistics
Note:
Pages:
6960–6984
Language:
URL:
https://aclanthology.org/2024.acl-long.376
DOI:
Bibkey:
Cite (ACL):
Siddhartha Jain, Xiaofei Ma, Anoop Deoras, and Bing Xiang. 2024. Lightweight reranking for language model generations. In Proceedings of the 62nd Annual Meeting of the Association for Computational Linguistics (Volume 1: Long Papers), pages 6960–6984, Bangkok, Thailand. Association for Computational Linguistics.
Cite (Informal):
Lightweight reranking for language model generations (Jain et al., ACL 2024)
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PDF:
https://aclanthology.org/2024.acl-long.376.pdf