How Does Personalized Memory Shape LLM Behavior? Benchmarking Rational Preference Utilization in Personalized Assistants

TL;DR

RPEval benchmark reveals personalized memory's impact on LLM behavior; RP-Reasoner significantly reduces irrational personalization.

cs.CL 🔴 Advanced 2026-01-23 3 views
Xueyang Feng Weinan Gan Xu Chen Quanyu Dai Yong Liu
personalization large language models memory mechanism user experience error analysis

Key Findings

Methodology

The study introduces the RPEval benchmark, comprising a personalized intent reasoning dataset and a multi-granularity evaluation protocol. By analyzing irrational personalization phenomena in existing LLMs, RP-Reasoner is developed, treating memory utilization as a pragmatic reasoning process for selective integration of personalized information.

Key Results

  • RP-Reasoner outperforms carefully designed baselines on RPEval, resolving 80% of bad cases in large-scale commercial assistants.
  • Experiments reveal a 40%-90% accuracy gap between mainstream LLMs and humans on rational personalization.
  • RP-Reasoner improves intent prediction accuracy by about 35% and reduces error severity by 26%.

Significance

This research reveals the dual effects of personalized memory in LLMs, providing new insights into improving user experience in personalized assistants. RP-Reasoner's pragmatic reasoning approach shows potential in mitigating irrational personalization, with significant academic and industrial implications.

Technical Contribution

The study proposes the Rational Personalization problem and develops the RPEval benchmark, providing the first systematic analysis of the dual effects of personalized memory. RP-Reasoner introduces pragmatic reasoning for memory utilization, offering new engineering possibilities and theoretical guarantees.

Novelty

This is the first study to propose the Rational Personalization problem, emphasizing consistency with the user's true intent rather than just memory. RP-Reasoner introduces pragmatic reasoning in memory utilization strategies, differing from existing methods.

Limitations

  • LLMs perform poorly in judging the applicability of each preference in multi-preference settings, with about a 40% accuracy gap from humans.
  • More capable LLMs perform worse at ignoring irrelevant preferences, possibly due to stronger contextual attention.

Future Work

Future research could explore more complex multi-preference scenarios, further optimize RP-Reasoner's reasoning mechanism, and validate its effectiveness in more practical applications.

AI Executive Summary

Recently, personalized assistants have integrated memory mechanisms powered by large language models (LLMs) to record user preferences for more aligned responses. However, this personalization also introduces irrelevant memories, interfering with LLMs' intent understanding. To investigate the dual effects of personalization, researchers developed the RPEval benchmark, which includes a personalized intent reasoning dataset and a multi-granularity evaluation protocol. RPEval reveals widespread irrational personalization in existing LLMs and, through error pattern analysis, illustrates its negative impact on user experience.

The study further introduces the RP-Reasoner method, treating memory utilization as a pragmatic reasoning process for selective integration of personalized information. Experimental results demonstrate that RP-Reasoner significantly outperforms carefully designed baselines on RPEval and resolves 80% of bad cases observed in large-scale commercial personalized assistants, highlighting the potential of pragmatic reasoning to mitigate irrational personalization.

This research not only provides new insights for improving personalized assistants but also lays the foundation for further studies on personalized memory utilization in academia and industry. Future research directions include exploring more complex multi-preference scenarios, optimizing reasoning mechanisms, and validating effectiveness in more practical applications.

Deep Analysis

Background

Personalized assistants have recently integrated memory mechanisms powered by large language models (LLMs) to record user preferences for more aligned responses. However, this personalization also introduces irrelevant memories, interfering with LLMs' intent understanding. To investigate the dual effects of personalization, researchers developed the RPEval benchmark, which includes a personalized intent reasoning dataset and a multi-granularity evaluation protocol.

Core Problem

The application of personalized memory in LLMs has dual effects: it can enhance user experience but also introduce irrelevant memories that interfere with intent understanding. Existing methods lack systematic analysis of this irrational personalization phenomenon.

Innovation

The study introduces the RPEval benchmark, providing the first systematic analysis of the dual effects of personalized memory. RP-Reasoner employs pragmatic reasoning for selective integration of personalized information, differing from existing methods.

Methodology

  • �� Develop the RPEval benchmark, including a personalized intent reasoning dataset and multi-granularity evaluation protocol.
  • �� Introduce RP-Reasoner, treating memory utilization as a pragmatic reasoning process.
  • �� Validate RP-Reasoner's superior performance on RPEval through experiments.

Experiments

Experiments were conducted on the RPEval benchmark, comparing RP-Reasoner with carefully designed baselines in personalized intent reasoning. Results show RP-Reasoner significantly outperforms baselines in resolving bad cases.

Results

Results indicate RP-Reasoner resolves 80% of bad cases on RPEval, significantly improves intent prediction accuracy, and reduces error severity.

Applications

RP-Reasoner can be applied in personalized assistants to enhance user experience and reduce irrational personalization. Its pragmatic reasoning approach can also inform other personalized systems.

Limitations & Outlook

RP-Reasoner's performance in multi-preference settings still has room for improvement. Future research could explore more complex scenarios and optimize reasoning mechanisms.

Plain Language Accessible to non-experts

Imagine you're at a restaurant, and the waiter remembers your past preferences, like your love for spicy food. But today, you want something mild. If the waiter only recommends spicy dishes based on past memories, it leads to a poor experience. Researchers developed a new method, RP-Reasoner, which acts like a smart waiter, selectively using past memories based on your current needs. This way, you get recommendations that match your current desires, not just past preferences. This method applies not only to restaurants but also to personalized assistants, helping them better understand and respond to user needs.

ELI14 Explained like you're 14

Imagine you're playing a game where your character remembers your past choices, like always choosing to attack. But this time, you want to try a defensive strategy. If the game character acts only on past choices, it messes up. Researchers created a new method, RP-Reasoner, like a smart game character, selectively using past choices based on your current strategy. This way, you can better control the character's actions, not limited by past choices. This method works not only in games but also in personalized assistants, helping them understand and respond to user needs better.

Glossary

Large Language Model (LLM)

An AI model capable of processing and generating natural language text, typically with billions of parameters.

Used in personalized assistants to generate more user-aligned responses.

Personalized Memory

A mechanism that records user preferences for generating personalized responses.

Used in personalized assistants to enhance user experience.

RPEval

A benchmark comprising a personalized intent reasoning dataset and multi-granularity evaluation protocol.

Used to evaluate rational personalization capabilities of assistants.

RP-Reasoner

A method treating memory utilization as a pragmatic reasoning process for selective integration of personalized information.

Significantly reduces irrational personalization in experiments.

Pragmatic Reasoning

A reasoning method based on practical application scenarios, emphasizing consistency with the user's true intent.

Used in RP-Reasoner for selective integration of personalized information.

Open Questions Unanswered questions from this research

  • 1 How to improve RP-Reasoner's reasoning capability in multi-preference scenarios? Current methods still have room for improvement in complex scenarios.
  • 2 How to enhance response accuracy of personalized assistants without increasing computational costs?

Applications

Immediate Applications

Personalized Assistants

RP-Reasoner can be used in personalized assistants to enhance user experience and reduce irrational personalization.

Long-term Vision

Intelligent Recommendation Systems

RP-Reasoner's method can be applied to intelligent recommendation systems, providing recommendations that better match current user needs.

Abstract

Large language model (LLM)-powered assistants have recently integrated memory mechanisms that record user preferences, leading to more personalized and user-aligned responses. However, irrelevant personalized memories are often introduced into the context, interfering with the LLM's intent understanding. To comprehensively investigate the dual effects of personalization, we develop RPEval, a benchmark comprising a personalized intent reasoning dataset and a multi-granularity evaluation protocol. RPEval reveals the widespread phenomenon of irrational personalization in existing LLMs and, through error pattern analysis, illustrates its negative impact on user experience. Finally, we introduce RP-Reasoner, which treats memory utilization as a pragmatic reasoning process, enabling the selective integration of personalized information. Experimental results demonstrate that our method significantly outperforms carefully designed baselines on RPEval, and resolves 80% of the bad cases observed in a large-scale commercial personalized assistant, highlighting the potential of pragmatic reasoning to mitigate irrational personalization. Our benchmark is publicly available at https://github.com/XueyangFeng/RPEval.

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