LLM-powered conversational assistants are often deployed in a one-size-fits-all manner, which fails to accommodate individual user preferences. Recently, LLM personalization -- tailoring models to align with specific user preferences -- has gained increasing attention as a way to bridge this gap. In this work, we specifically focus on a practical yet challenging setting where only a small set of preference annotations can be collected per user -- a problem we define as Personalized Preference Alignment with Limited Data (PPALLI). To support research in this area, we introduce two datasets -- DnD and ELIP -- and benchmark a variety of alignment techniques on them. We further propose FaST, a highly parameter-efficient approach that leverages high-level features automatically discovered from the data, achieving the best overall performance.
@article{arxiv.2508.04698,
title = {FaST: Feature-aware Sampling and Tuning for Personalized Preference Alignment with Limited Data},
author = {Thibaut Thonet and Germán Kruszewski and Jos Rozen and Pierre Erbacher and Marc Dymetman},
journal= {arXiv preprint arXiv:2508.04698},
year = {2025}
}