Pointwise Mutual Information as a Performance Gauge for Retrieval-Augmented Generation

Fuente: arXiv
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Main Authors: Liu, Tianyu, Qi, Jirui, He, Paul, Bisazza, Arianna, Sachan, Mrinmaya, Cotterell, Ryan
Format: Preprint
Published: 2024
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author Liu, Tianyu
Qi, Jirui
He, Paul
Bisazza, Arianna
Sachan, Mrinmaya
Cotterell, Ryan
author_facet Liu, Tianyu
Qi, Jirui
He, Paul
Bisazza, Arianna
Sachan, Mrinmaya
Cotterell, Ryan
contents Recent work suggests that large language models enhanced with retrieval-augmented generation are easily influenced by the order, in which the retrieved documents are presented to the model when solving tasks such as question answering (QA). However, there is no method to date that exploits this phenomenon to improve generation. We fill this gap. In this study, we show that the pointwise mutual information between a context and a question is an effective gauge for language model performance. Importantly, this gauge does not depend on knowing the answer to the question a priori. Through experiments on two question-answering datasets and a variety of large language models, we find evidence for an empirical correlation between answer accuracy and pointwise mutual information. Additionally, we propose two methods that use the pointwise mutual information between a document and a question as a gauge for selecting and constructing prompts that lead to better performance, whose effectiveness we demonstrate through experimentation.
format Preprint
id arxiv_https___arxiv_org_abs_2411_07773
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Pointwise Mutual Information as a Performance Gauge for Retrieval-Augmented Generation
Liu, Tianyu
Qi, Jirui
He, Paul
Bisazza, Arianna
Sachan, Mrinmaya
Cotterell, Ryan
Computation and Language
Artificial Intelligence
Machine Learning
Recent work suggests that large language models enhanced with retrieval-augmented generation are easily influenced by the order, in which the retrieved documents are presented to the model when solving tasks such as question answering (QA). However, there is no method to date that exploits this phenomenon to improve generation. We fill this gap. In this study, we show that the pointwise mutual information between a context and a question is an effective gauge for language model performance. Importantly, this gauge does not depend on knowing the answer to the question a priori. Through experiments on two question-answering datasets and a variety of large language models, we find evidence for an empirical correlation between answer accuracy and pointwise mutual information. Additionally, we propose two methods that use the pointwise mutual information between a document and a question as a gauge for selecting and constructing prompts that lead to better performance, whose effectiveness we demonstrate through experimentation.
title Pointwise Mutual Information as a Performance Gauge for Retrieval-Augmented Generation
topic Computation and Language
Artificial Intelligence
Machine Learning
url https://arxiv.org/abs/2411.07773