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Main Authors: Horter, Tiffany, Markham, Andrew, Trigoni, Niki, Booth, Serena
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2605.06895
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author Horter, Tiffany
Markham, Andrew
Trigoni, Niki
Booth, Serena
author_facet Horter, Tiffany
Markham, Andrew
Trigoni, Niki
Booth, Serena
contents How can we make models robust to even imperfect human feedback? In reinforcement learning from human feedback (RLHF), human preferences over model outputs are used to train a reward model that assigns scalar values to responses. Because these rewards are inferred from pairwise comparisons, this learning depends on an assumed relationship between latent reward differences and observed preferences, typically modeled using a Boltzmann formulation in which a rationality parameter beta informs how consistently preferences reflect reward differences. In practice, beta is typically treated as a fixed constant that reflects assumed uniform annotator reliability. However, human feedback is not this simplistic in practice: real human judgments are shaped by cognitive biases, leading to systematic deviations from reward-consistent behavior that arise contextually. To address this, we treat rationality as context- and annotation-dependent. We design an approach to dynamically adjust the rationality parameter beta during reward learning using an LLM-as-judge to assess the likely presence of cognitive biases. This approach effectively downweights comparisons that are likely to reflect biased or unreliable judgments. Empirically, we show that this approach learns a more rational downstream model, even when finetuning on datasets with strongly biased preferences.
format Preprint
id arxiv_https___arxiv_org_abs_2605_06895
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Mitigating Cognitive Bias in RLHF by Altering Rationality
Horter, Tiffany
Markham, Andrew
Trigoni, Niki
Booth, Serena
Artificial Intelligence
How can we make models robust to even imperfect human feedback? In reinforcement learning from human feedback (RLHF), human preferences over model outputs are used to train a reward model that assigns scalar values to responses. Because these rewards are inferred from pairwise comparisons, this learning depends on an assumed relationship between latent reward differences and observed preferences, typically modeled using a Boltzmann formulation in which a rationality parameter beta informs how consistently preferences reflect reward differences. In practice, beta is typically treated as a fixed constant that reflects assumed uniform annotator reliability. However, human feedback is not this simplistic in practice: real human judgments are shaped by cognitive biases, leading to systematic deviations from reward-consistent behavior that arise contextually. To address this, we treat rationality as context- and annotation-dependent. We design an approach to dynamically adjust the rationality parameter beta during reward learning using an LLM-as-judge to assess the likely presence of cognitive biases. This approach effectively downweights comparisons that are likely to reflect biased or unreliable judgments. Empirically, we show that this approach learns a more rational downstream model, even when finetuning on datasets with strongly biased preferences.
title Mitigating Cognitive Bias in RLHF by Altering Rationality
topic Artificial Intelligence
url https://arxiv.org/abs/2605.06895