Rejected Dialects: Biases Against African American Language in Reward Models

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Mire, Joel, Aysola, Zubin Trivadi, Chechelnitsky, Daniel, Deas, Nicholas, Zerva, Chrysoula, Sap, Maarten
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866915158177087488
author Mire, Joel
Aysola, Zubin Trivadi
Chechelnitsky, Daniel
Deas, Nicholas
Zerva, Chrysoula
Sap, Maarten
author_facet Mire, Joel
Aysola, Zubin Trivadi
Chechelnitsky, Daniel
Deas, Nicholas
Zerva, Chrysoula
Sap, Maarten
contents Preference alignment via reward models helps build safe, helpful, and reliable large language models (LLMs). However, subjectivity in preference judgments and the lack of representative sampling in preference data collection can introduce new biases, hindering reward models' fairness and equity. In this work, we introduce a framework for evaluating dialect biases in reward models and conduct a case study on biases against African American Language (AAL) through several experiments comparing reward model preferences and behavior on paired White Mainstream English (WME) and both machine-translated and human-written AAL corpora. We show that reward models are less aligned with human preferences when processing AAL texts vs. WME ones (-4\% accuracy on average), frequently disprefer AAL-aligned texts vs. WME-aligned ones, and steer conversations toward WME, even when prompted with AAL texts. Our findings provide a targeted analysis of anti-AAL biases at a relatively understudied stage in LLM development, highlighting representational harms and ethical questions about the desired behavior of LLMs concerning AAL.
format Preprint
id arxiv_https___arxiv_org_abs_2502_12858
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Rejected Dialects: Biases Against African American Language in Reward Models
Mire, Joel
Aysola, Zubin Trivadi
Chechelnitsky, Daniel
Deas, Nicholas
Zerva, Chrysoula
Sap, Maarten
Computation and Language
Artificial Intelligence
Computers and Society
I.2.7; K.4.2
Preference alignment via reward models helps build safe, helpful, and reliable large language models (LLMs). However, subjectivity in preference judgments and the lack of representative sampling in preference data collection can introduce new biases, hindering reward models' fairness and equity. In this work, we introduce a framework for evaluating dialect biases in reward models and conduct a case study on biases against African American Language (AAL) through several experiments comparing reward model preferences and behavior on paired White Mainstream English (WME) and both machine-translated and human-written AAL corpora. We show that reward models are less aligned with human preferences when processing AAL texts vs. WME ones (-4\% accuracy on average), frequently disprefer AAL-aligned texts vs. WME-aligned ones, and steer conversations toward WME, even when prompted with AAL texts. Our findings provide a targeted analysis of anti-AAL biases at a relatively understudied stage in LLM development, highlighting representational harms and ethical questions about the desired behavior of LLMs concerning AAL.
title Rejected Dialects: Biases Against African American Language in Reward Models
topic Computation and Language
Artificial Intelligence
Computers and Society
I.2.7; K.4.2
url https://arxiv.org/abs/2502.12858