When Can Proxies Improve the Sample Complexity of Preference Learning?

Fuente: arXiv
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Main Authors: Zhu, Yuchen, de Souza, Daniel Augusto, Shi, Zhengyan, Yang, Mengyue, Minervini, Pasquale, D'Amour, Alexander, Kusner, Matt J.
Format: Preprint
Published: 2024
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author Zhu, Yuchen
de Souza, Daniel Augusto
Shi, Zhengyan
Yang, Mengyue
Minervini, Pasquale
D'Amour, Alexander
Kusner, Matt J.
author_facet Zhu, Yuchen
de Souza, Daniel Augusto
Shi, Zhengyan
Yang, Mengyue
Minervini, Pasquale
D'Amour, Alexander
Kusner, Matt J.
contents We address the problem of reward hacking, where maximising a proxy reward does not necessarily increase the true reward. This is a key concern for Large Language Models (LLMs), as they are often fine-tuned on human preferences that may not accurately reflect a true objective. Existing work uses various tricks such as regularisation, tweaks to the reward model, and reward hacking detectors, to limit the influence that such proxy preferences have on a model. Luckily, in many contexts such as medicine, education, and law, a sparse amount of expert data is often available. In these cases, it is often unclear whether the addition of proxy data can improve policy learning. We outline a set of sufficient conditions on proxy feedback that, if satisfied, indicate that proxy data can provably improve the sample complexity of learning the ground truth policy. These conditions can inform the data collection process for specific tasks. The result implies a parameterisation for LLMs that achieves this improved sample complexity. We detail how one can adapt existing architectures to yield this improved sample complexity.
format Preprint
id arxiv_https___arxiv_org_abs_2412_16475
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle When Can Proxies Improve the Sample Complexity of Preference Learning?
Zhu, Yuchen
de Souza, Daniel Augusto
Shi, Zhengyan
Yang, Mengyue
Minervini, Pasquale
D'Amour, Alexander
Kusner, Matt J.
Machine Learning
Artificial Intelligence
We address the problem of reward hacking, where maximising a proxy reward does not necessarily increase the true reward. This is a key concern for Large Language Models (LLMs), as they are often fine-tuned on human preferences that may not accurately reflect a true objective. Existing work uses various tricks such as regularisation, tweaks to the reward model, and reward hacking detectors, to limit the influence that such proxy preferences have on a model. Luckily, in many contexts such as medicine, education, and law, a sparse amount of expert data is often available. In these cases, it is often unclear whether the addition of proxy data can improve policy learning. We outline a set of sufficient conditions on proxy feedback that, if satisfied, indicate that proxy data can provably improve the sample complexity of learning the ground truth policy. These conditions can inform the data collection process for specific tasks. The result implies a parameterisation for LLMs that achieves this improved sample complexity. We detail how one can adapt existing architectures to yield this improved sample complexity.
title When Can Proxies Improve the Sample Complexity of Preference Learning?
topic Machine Learning
Artificial Intelligence
url https://arxiv.org/abs/2412.16475