Learning Preference Adaptation for Large Language Model Personalization via Verbal Reinforcement Learning

TL;DR

AlignXada uses verbal reinforcement learning for LLM personalization, achieving a 3.82-point gain while reducing 77.2% redundancy.

cs.CL 🔴 Advanced 2026-08-10 2 views
Yuting Liu Wei Wu Jianzhe Zhao Guibing Guo
large language model personalization verbal reinforcement learning meta-learning task adaptation

Key Findings

Methodology

AlignXada is a training-free meta-learning framework that induces reusable textual refinement policies to adapt universal preference summaries to task-specific representations. It uses a meta learner to generate policies, which are iteratively optimized using verbal reinforcement learning.

Key Results

  • AlignXada improved 33 out of 39 task-model cells with an average gain of 3.82 points, retaining only 22.8% of the original information.
  • On the PersonaMem-v2 dataset, 97.5% of refined preferences were consistent with source preferences, retaining 83.3% of task-relevant signals.
  • AlignXada outperformed RAG in 36 cells, demonstrating advantages beyond query-level retrieval.

Significance

This study addresses the distraction caused by redundant information in universal preference summaries, enhancing the efficiency and accuracy of personalized AI agents. It provides a practical complement to memory construction for lifelong personalized agents, impacting both academia and industry.

Technical Contribution

AlignXada introduces a novel separation of policy generation and preference refinement, making the adaptation process transparent and controllable. By using verbal reinforcement learning, it avoids parameter updates, supporting both open-source and proprietary models, offering new engineering possibilities.

Novelty

AlignXada is the first to apply verbal reinforcement learning for preference adaptation in LLMs, differing from traditional preference summarization methods by achieving task-specific personalization through policy generation.

Limitations

  • In complex tasks, the refinement policy may not fully eliminate all distracting information.
  • Relies on high-quality task-specific demonstration sets for policy generation.

Future Work

Future research could explore applying AlignXada to more tasks and models, and optimize the policy generation process to improve adaptation efficiency.

AI Executive Summary

Personalization in large language models is crucial, yet universal preference summaries often contain irrelevant information for specific tasks, leading to wasted context capacity and cross-task distraction. AlignXada addresses this through task-specific preference adaptation using verbal reinforcement learning.

AlignXada is a training-free meta-learning framework that generates reusable textual refinement policies to adapt universal preference summaries to task-specific representations. It optimizes these policies through verbal reinforcement learning, avoiding parameter updates and supporting both open-source and proprietary models.

Experimental results show that AlignXada improved 33 out of 39 task-model cells with an average gain of 3.82 points, retaining only 22.8% of the original information, outperforming RAG. This indicates its significant value in memory construction for personalized AI agents.

Deep Analysis

Background

With the rise of personalized AI agents, LLMs are increasingly used in search, recommendation, and dialogue systems. Personalization techniques are key to building LLM memories, yet universal preference summaries often introduce distraction due to redundant information.

Core Problem

Universal preference summaries contain a lot of information irrelevant to specific tasks, wasting context capacity and introducing distraction. Manually designing task-specific views is hard to scale.

Innovation

AlignXada uses verbal reinforcement learning to generate textual refinement policies, automatically adapting universal preference summaries to task-specific representations, avoiding the challenges of manual design.

Methodology

  • �� Use a meta learner to generate textual refinement policies
  • �� Optimize policies through verbal reinforcement learning
  • �� Adapt universal preference summaries to task-specific representations
  • �� Support both open-source and proprietary models, avoiding parameter updates

Experiments

AlignXada was evaluated on 13 tasks and 3 downstream models, covering 39 task-model cells. It used the PersonaMem-v2 and MemoryCD datasets to assess policy generation and refinement effectiveness.

Results

AlignXada improved 33 out of 39 task-model cells with an average gain of 3.82 points, retaining only 22.8% of the original information, outperforming RAG, demonstrating superior task adaptation capabilities.

Applications

AlignXada can be used in memory construction for personalized AI agents, enhancing personalization in search, recommendation, and dialogue systems.

Limitations & Outlook

In complex tasks, the refinement policy may not fully eliminate all distracting information. Relies on high-quality task-specific demonstration sets for policy generation.

Plain Language Accessible to non-experts

Imagine organizing a large bookshelf where each book represents a user preference, and the shelf represents a universal preference summary. AlignXada acts like a smart librarian, selecting the most relevant books based on your current reading needs and temporarily removing unrelated ones. This allows you to focus on the information needed for the current task without being distracted by other books.

ELI14 Explained like you're 14

Imagine you have a huge toy box filled with all sorts of toys. Each toy represents something you like. Now, you want to play a specific game but don't need all the toys. AlignXada is like a smart helper that picks out the best toys for that game and puts the others back in the box. This way, you can focus on playing the game without getting distracted by other toys.

Glossary

Large Language Model (LLM)

A type of large neural network model capable of processing and generating natural language.

Used for building personalized AI agents.

Meta-learning

A method of learning how to learn, aimed at improving model learning efficiency.

Used to generate textual refinement policies.

Verbal Reinforcement Learning

A learning method that optimizes policies using natural language feedback.

Used to optimize AlignXada's refinement policies.

Task-specific Preference Adaptation

Adjusting universal preference summaries to task-specific preference representations.

Core functionality of AlignXada.

Textual Refinement Policy

A policy used to adjust and optimize textual information.

AlignXada uses this policy for preference adaptation.

Open Questions Unanswered questions from this research

  • 1 How can AlignXada be applied to a wider range of tasks and models?
  • 2 How to improve the efficiency of the policy generation process?

Applications

Immediate Applications

Personalized Recommendations

AlignXada can optimize personalization in recommendation systems, enhancing user experience.

Long-term Vision

Long-term Personalized Agents

AlignXada can be used to build long-term personalized AI agents, supporting the continuous evolution of user preferences.

Abstract

Natural language user preferences provide an interpretable interface for LLM personalization. However, universal preference summaries often contain information irrelevant to a particular downstream task. Directly supplying the full preference summary therefore wastes context capacity and introduces cross-task distraction, while manually designing task-specific preference views is difficult to scale. In this work, we study \emph{task-specific preference adaptation}: given a universal user preference summary and a downstream task, derive a task-conditioned representation that preserves sufficient decision-relevant evidence while removing redundant context. To this end, we propose \textsc{AlignXada}, a training-free meta-learning framework that induces reusable textual refinement policies for adapting universal preference summaries to task-specific ones. The refinement policy is iteratively optimized by a meta learner through verbal reinforcement learning. Across 13 tasks and three downstream models (39 task--model cells), \textsc{AlignXada} achieves an average gain of 3.82 points, improving 33 cells while retaining only 22.8\% of the original profile tokens and outperforming RAG in 36 cells. An extended faithfulness analysis further shows that the refined profiles remain largely grounded in the source preferences while preserving task-relevant personalization signals, suggesting that profile-side adaptation serves as a practical complement to universal memory construction for lifelong personalized agents.

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