PsPLUG: explicit style instructions cause 'personalization collapse' in LLMs, lightweight plug-in fixes it

Yutong Song · hf · 2026-09-28

Personalized LLMs are often expected to follow explicit style instructions, but the paper finds such instructions can undermine the user-specific characteristics personalization methods aim to preserve — a failure mode the authors call "personalization collapse."

They propose PsPLUG, a lightweight plug-in that learns a user-specific residual after accounting for the requested style, and allows tuning personalization strength at inference time. Experiments show existing methods degrade under explicit style instructions, whereas PsPLUG better preserves user preferences while providing precise control over the personalization-style balance.

Original post →

More from Research

Research channel →