EVALUESTEER: Measuring Reward Model Steerability Towards Values and Preferences

Kshitish Ghate, Andy Liu, Devansh Jain, Taylor Sorensen, Atoosa Kasirzadeh, Aylin Caliskan, Mona T. Diab, Maarten Sap


Abstract
As large language models (LLMs) are deployed globally, creating pluralistic systems that can accommodate the diverse preferences and values of users becomes essential. We introduce EVALUESTEER, a human-validated benchmark to measure the steerability of LLM and reward models (RMs) to users’ value and stylistic preference profiles grounded in psychology and literature on human-LLM interaction. To address the gap in existing datasets that do not support controlled evaluations of RM steering, we synthetically generated 165,888 preference pairs – systematically varying pairs along 4 value dimensions (traditional, secular-rational, survival, and self-expression) and 4 style dimensions (verbosity, readability, confidence, warmth). We use EVALUESTEER to evaluate whether, given a user profile and a pair of candidate value and style laden responses, LLMs and RMs are able to select the output that aligns with the user’s preferences. Our results show that, when given the user’s full profile of values and stylistic preferences, the best models achieve <75% accuracy in choosing the correct response, in contrast to > 99% accuracy when only relevant style and value preferences are provided. RMs also exhibit systematic biases, favoring secular values and verbose, confident language, and prioritizing style alignment over value alignment when the two conflict. EVALUESTEER thus highlights the limitations of current RMs at identifying and adapting to relevant user profile information, and provides a challenging testbed for developing RMs that can be steered towards diverse human values and preferences.
Anthology ID:
2026.findings-emnlp.572
Volume:
Findings of the Association for Computational Linguistics: EMNLP 2026
Month:
October
Year:
2026
Address:
Budapest, Hungary
Editors:
Hung-Yi Lee, Sunipa Dev, Jessy Li, Desmond Elliott
Venue:
Findings
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SIGDAT
Publisher:
Association for Computational Linguistics
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Pages:
12072–12099
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URL:
https://aclanthology.org/2026.findings-emnlp.572/
DOI:
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Cite (ACL):
Kshitish Ghate, Andy Liu, Devansh Jain, Taylor Sorensen, Atoosa Kasirzadeh, Aylin Caliskan, Mona T. Diab, and Maarten Sap. 2026. EVALUESTEER: Measuring Reward Model Steerability Towards Values and Preferences. In Findings of the Association for Computational Linguistics: EMNLP 2026, pages 12072–12099, Budapest, Hungary. Association for Computational Linguistics.
Cite (Informal):
EVALUESTEER: Measuring Reward Model Steerability Towards Values and Preferences (Ghate et al., Findings 2026)
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https://aclanthology.org/2026.findings-emnlp.572.pdf