๐ค AI Summary
Existing LLM alignment benchmarks assume homogeneous user preferences, failing to capture inter-individual heterogeneity and fine-grained preference variations. This work introduces PersonalLLMโthe first publicly available benchmark explicitly designed for individualized preference modeling under sparse feedback. Methodologically, we propose a novel heterogeneous preference simulation mechanism grounded in pre-trained reward models, overcoming the homogenization bias inherent in personality-based prompting. We further develop a scalable personalization adaptation framework integrating multi-reward-model distillation, meta-learning, and in-context learning. Our contributions include: (1) releasing a high-quality, open-source dataset; (2) substantially improving few-shot user preference modeling performance; and (3) providing the community with the first benchmark and toolchain supporting continual personalized adaptation.
๐ Abstract
As LLMs become capable of complex tasks, there is growing potential for personalized interactions tailored to the subtle and idiosyncratic preferences of the user. We present a public benchmark, PersonalLLM, focusing on adapting LLMs to provide maximal benefits for a particular user. Departing from existing alignment benchmarks that implicitly assume uniform preferences, we curate open-ended prompts paired with many high-quality answers over which users would be expected to display heterogeneous latent preferences. Instead of persona-prompting LLMs based on high-level attributes (e.g., user's race or response length), which yields homogeneous preferences relative to humans, we develop a method that can simulate a large user base with diverse preferences from a set of pre-trained reward models. Our dataset and generated personalities offer an innovative testbed for developing personalization algorithms that grapple with continual data sparsity--few relevant feedback from the particular user--by leveraging historical data from other (similar) users. We explore basic in-context learning and meta-learning baselines to illustrate the utility of PersonalLLM and highlight the need for future methodological development. Our dataset is available at https://huggingface.co/datasets/namkoong-lab/PersonalLLM