@inproceedings{goyal-etal-2026-vastu,
title = "{VASTU}: Language Models Struggle to Recognize Online Community Values",
author = "Goyal, Agam and
Zhan, Xianyang and
Lambert, Charlotte and
Saha, Koustuv and
Chandrasekharan, Eshwar",
editor = "Lee, Hung-Yi and
Dev, Sunipa and
Li, Jessy and
Elliott, Desmond",
booktitle = "Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing",
month = oct,
year = "2026",
address = "Budapest, Hungary",
publisher = "Association for Computational Linguistics",
url = "https://aclanthology.org/2026.emnlp-main.231/",
pages = "5311--5327",
ISBN = "979-8-89176-459-0",
abstract = "Online communities develop distinct norms for content they collectively value, yet it remains unclear whether current language models can recognize locally valued contributions in context. We formalize this as \textbf{community-conditioned preference prediction} and introduce \textsc{Vastu} (\underline{V}alue-\underline{A}ware \underline{S}ocial \underline{Tu}ning), a benchmark of 75,000 Reddit comments from 15 communities spanning Gaming, Science, Q{\&}A, Advice, and Politics. We evaluate four model families{---}prompted LLMs, LoRA-adapted SLMs, supervised encoders, and feature-based classifiers{---}across global, local, and context-conditioned settings. Our central finding is that parametric adaptation consistently outperforms prompting: supervised encoders reach 0.74 AUROC and fine-tuned SLMs 0.64{--}0.71, while the best prompted result is only 0.62. This gap is not merely quantitative{---}vanilla prompting yields over 80{\%} false-negative rates, systematically discarding content communities actually value. Conversational context narrows but does not close this divide. Together, these results suggest that local preference recognition requires community-specific training signal, not just better prompting. Our work supports future research on community-aware reward modeling, feed curation, and positive moderation."
}<?xml version="1.0" encoding="UTF-8"?>
<modsCollection xmlns="http://www.loc.gov/mods/v3">
<mods ID="goyal-etal-2026-vastu">
<titleInfo>
<title>VASTU: Language Models Struggle to Recognize Online Community Values</title>
</titleInfo>
<name type="personal">
<namePart type="given">Agam</namePart>
<namePart type="family">Goyal</namePart>
<role>
<roleTerm authority="marcrelator" type="text">author</roleTerm>
</role>
</name>
<name type="personal">
<namePart type="given">Xianyang</namePart>
<namePart type="family">Zhan</namePart>
<role>
<roleTerm authority="marcrelator" type="text">author</roleTerm>
</role>
</name>
<name type="personal">
<namePart type="given">Charlotte</namePart>
<namePart type="family">Lambert</namePart>
<role>
<roleTerm authority="marcrelator" type="text">author</roleTerm>
</role>
</name>
<name type="personal">
<namePart type="given">Koustuv</namePart>
<namePart type="family">Saha</namePart>
<role>
<roleTerm authority="marcrelator" type="text">author</roleTerm>
</role>
</name>
<name type="personal">
<namePart type="given">Eshwar</namePart>
<namePart type="family">Chandrasekharan</namePart>
<role>
<roleTerm authority="marcrelator" type="text">author</roleTerm>
</role>
</name>
<originInfo>
<dateIssued>2026-10</dateIssued>
</originInfo>
<typeOfResource>text</typeOfResource>
<relatedItem type="host">
<titleInfo>
<title>Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing</title>
</titleInfo>
<name type="personal">
<namePart type="given">Hung-Yi</namePart>
<namePart type="family">Lee</namePart>
<role>
<roleTerm authority="marcrelator" type="text">editor</roleTerm>
</role>
</name>
<name type="personal">
<namePart type="given">Sunipa</namePart>
<namePart type="family">Dev</namePart>
<role>
<roleTerm authority="marcrelator" type="text">editor</roleTerm>
</role>
</name>
<name type="personal">
<namePart type="given">Jessy</namePart>
<namePart type="family">Li</namePart>
<role>
<roleTerm authority="marcrelator" type="text">editor</roleTerm>
</role>
</name>
<name type="personal">
<namePart type="given">Desmond</namePart>
<namePart type="family">Elliott</namePart>
<role>
<roleTerm authority="marcrelator" type="text">editor</roleTerm>
</role>
</name>
<originInfo>
<publisher>Association for Computational Linguistics</publisher>
<place>
<placeTerm type="text">Budapest, Hungary</placeTerm>
</place>
</originInfo>
<genre authority="marcgt">conference publication</genre>
<identifier type="isbn">979-8-89176-459-0</identifier>
</relatedItem>
<abstract>Online communities develop distinct norms for content they collectively value, yet it remains unclear whether current language models can recognize locally valued contributions in context. We formalize this as community-conditioned preference prediction and introduce Vastu (\underlineValue-\underlineAware \underlineSocial \underlineTuning), a benchmark of 75,000 Reddit comments from 15 communities spanning Gaming, Science, Q&A, Advice, and Politics. We evaluate four model families—prompted LLMs, LoRA-adapted SLMs, supervised encoders, and feature-based classifiers—across global, local, and context-conditioned settings. Our central finding is that parametric adaptation consistently outperforms prompting: supervised encoders reach 0.74 AUROC and fine-tuned SLMs 0.64–0.71, while the best prompted result is only 0.62. This gap is not merely quantitative—vanilla prompting yields over 80% false-negative rates, systematically discarding content communities actually value. Conversational context narrows but does not close this divide. Together, these results suggest that local preference recognition requires community-specific training signal, not just better prompting. Our work supports future research on community-aware reward modeling, feed curation, and positive moderation.</abstract>
<identifier type="citekey">goyal-etal-2026-vastu</identifier>
<location>
<url>https://aclanthology.org/2026.emnlp-main.231/</url>
</location>
<part>
<date>2026-10</date>
<extent unit="page">
<start>5311</start>
<end>5327</end>
</extent>
</part>
</mods>
</modsCollection>
%0 Conference Proceedings
%T VASTU: Language Models Struggle to Recognize Online Community Values
%A Goyal, Agam
%A Zhan, Xianyang
%A Lambert, Charlotte
%A Saha, Koustuv
%A Chandrasekharan, Eshwar
%Y Lee, Hung-Yi
%Y Dev, Sunipa
%Y Li, Jessy
%Y Elliott, Desmond
%S Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing
%D 2026
%8 October
%I Association for Computational Linguistics
%C Budapest, Hungary
%@ 979-8-89176-459-0
%F goyal-etal-2026-vastu
%X Online communities develop distinct norms for content they collectively value, yet it remains unclear whether current language models can recognize locally valued contributions in context. We formalize this as community-conditioned preference prediction and introduce Vastu (\underlineValue-\underlineAware \underlineSocial \underlineTuning), a benchmark of 75,000 Reddit comments from 15 communities spanning Gaming, Science, Q&A, Advice, and Politics. We evaluate four model families—prompted LLMs, LoRA-adapted SLMs, supervised encoders, and feature-based classifiers—across global, local, and context-conditioned settings. Our central finding is that parametric adaptation consistently outperforms prompting: supervised encoders reach 0.74 AUROC and fine-tuned SLMs 0.64–0.71, while the best prompted result is only 0.62. This gap is not merely quantitative—vanilla prompting yields over 80% false-negative rates, systematically discarding content communities actually value. Conversational context narrows but does not close this divide. Together, these results suggest that local preference recognition requires community-specific training signal, not just better prompting. Our work supports future research on community-aware reward modeling, feed curation, and positive moderation.
%U https://aclanthology.org/2026.emnlp-main.231/
%P 5311-5327
Markdown (Informal)
[VASTU: Language Models Struggle to Recognize Online Community Values](https://aclanthology.org/2026.emnlp-main.231/) (Goyal et al., EMNLP 2026)
ACL