Linguistic Nepotism: Trading-off Quality for Language Preference in Multilingual RAG

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Ki, Dayeon, Carpuat, Marine, McNamee, Paul, Khashabi, Daniel, Yang, Eugene, Lawrie, Dawn, Duh, Kevin
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866914071183360000
author Ki, Dayeon
Carpuat, Marine
McNamee, Paul
Khashabi, Daniel
Yang, Eugene
Lawrie, Dawn
Duh, Kevin
author_facet Ki, Dayeon
Carpuat, Marine
McNamee, Paul
Khashabi, Daniel
Yang, Eugene
Lawrie, Dawn
Duh, Kevin
contents Multilingual Retrieval-Augmented Generation (mRAG) systems enable language models to answer knowledge-intensive queries with citation-supported responses across languages. While such systems have been proposed, an open questions is whether the mixture of different document languages impacts generation and citation in unintended ways. To investigate, we introduce a controlled methodology using model internals to measure language preference while holding other factors such as document relevance constant. Across eight languages and six open-weight models, we find that models preferentially cite English sources when queries are in English, with this bias amplified for lower-resource languages and for documents positioned mid-context. Crucially, we find that models sometimes trade-off document relevance for language preference, indicating that citation choices are not always driven by informativeness alone. Our findings shed light on how language models leverage multilingual context and influence citation behavior.
format Preprint
id arxiv_https___arxiv_org_abs_2509_13930
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Linguistic Nepotism: Trading-off Quality for Language Preference in Multilingual RAG
Ki, Dayeon
Carpuat, Marine
McNamee, Paul
Khashabi, Daniel
Yang, Eugene
Lawrie, Dawn
Duh, Kevin
Computation and Language
Multilingual Retrieval-Augmented Generation (mRAG) systems enable language models to answer knowledge-intensive queries with citation-supported responses across languages. While such systems have been proposed, an open questions is whether the mixture of different document languages impacts generation and citation in unintended ways. To investigate, we introduce a controlled methodology using model internals to measure language preference while holding other factors such as document relevance constant. Across eight languages and six open-weight models, we find that models preferentially cite English sources when queries are in English, with this bias amplified for lower-resource languages and for documents positioned mid-context. Crucially, we find that models sometimes trade-off document relevance for language preference, indicating that citation choices are not always driven by informativeness alone. Our findings shed light on how language models leverage multilingual context and influence citation behavior.
title Linguistic Nepotism: Trading-off Quality for Language Preference in Multilingual RAG
topic Computation and Language
url https://arxiv.org/abs/2509.13930