Large Language Models Are Semi-Parametric Reinforcement Learning Agents

TL;DR

REMEMBERER framework enhances LLM's RL capabilities with long-term experience memory, achieving a 4% success rate increase.

cs.CL 🔴 Advanced 2023-06-09 2 views
Danyang Zhang Lu Chen Situo Zhang Hongshen Xu Zihan Zhao Kai Yu
Large Language Model Reinforcement Learning Experience Memory Self-evolving Cross-task

Key Findings

Methodology

The REMEMBERER framework combines large language models (LLMs) with experience memory, introducing the RLEM (Reinforcement Learning with Experience Memory) mechanism. This enables LLMs to evolve without parameter tuning by leveraging past successes and failures to optimize decision-making. Core components include an LLM decision module and an external experience memory module, which is continuously updated through the RL process.

Key Results

  • REMEMBERER achieved a 4% success rate increase on the WebShop task set and a 2% increase on the WikiHow task set, significantly outperforming previous SOTA models.
  • The framework demonstrated higher stability and robustness across different initializations and training sets.
  • Ablation studies showed that long-term experience memory is more effective than short-term working memory.

Significance

The REMEMBERER framework enhances reinforcement learning efficiency and effectiveness by leveraging experience memory without requiring LLM parameter fine-tuning. This approach addresses previous bottlenecks in handling interaction experiences, offering a more cost-effective solution for academia and industry, especially in cross-task learning scenarios.

Technical Contribution

REMEMBERER introduces external experience memory, breaking the dependency on parameter tuning in traditional RL methods, providing a semi-parametric solution. This reduces computational overhead and enhances model adaptability.

Novelty

REMEMBERER is the first to integrate long-term experience memory with LLMs, proposing a self-evolving mechanism without parameter tuning, significantly improving cross-task learning compared to existing short-term memory methods.

Limitations

  • REMEMBERER may face memory capacity limitations in handling extremely complex tasks, affecting performance.
  • The initialization of experience memory may impact final outcomes in certain tasks.

Future Work

Future research could explore optimizing the structure and update strategy of experience memory to further enhance REMEMBERER's performance on larger task sets. Additionally, integrating other machine learning methods, such as meta-learning, may lead to new breakthroughs.

AI Executive Summary

The REMEMBERER framework significantly enhances the performance of large language models in reinforcement learning tasks by introducing long-term experience memory. Traditional LLMs often rely on parameter fine-tuning to handle interaction experiences, which is both time-consuming and costly. REMEMBERER optimizes decision-making through the RLEM mechanism by leveraging past successes and failures, avoiding frequent model adjustments.

In experiments, REMEMBERER achieved a 4% success rate increase on the WebShop task set and a 2% increase on the WikiHow task set, outperforming existing SOTA models. By utilizing long-term experience memory, REMEMBERER demonstrated higher stability and robustness across different initializations and training sets.

While REMEMBERER excels in many aspects, it may face memory capacity limitations when handling extremely complex tasks. Future research could explore optimizing the structure and update strategy of experience memory to further enhance its performance on larger task sets.

Deep Analysis

Background

In recent years, large language models (LLMs) have excelled in natural language processing tasks, but effectively utilizing interaction experiences in reinforcement learning remains a challenge. Traditional methods like parameter fine-tuning, though effective, are costly. REMEMBERER offers a new solution by introducing long-term experience memory.

Core Problem

Existing LLMs struggle to effectively utilize interaction experiences in reinforcement learning due to the need for frequent parameter tuning, which is both time-consuming and costly. Additionally, short-term memory methods cannot leverage experiences across tasks.

Innovation

REMEMBERER's core innovation lies in combining long-term experience memory with LLMs, achieving self-evolution through the RLEM mechanism without parameter tuning. Compared to traditional methods, REMEMBERER can leverage experiences across tasks, improving learning efficiency.

Methodology

  • �� REMEMBERER framework consists of an LLM decision module and an experience memory module.
  • �� Experience memory is continuously updated through the RLEM mechanism, storing interaction experiences.
  • �� LLM references past successes and failures in the experience memory to optimize current decisions.

Experiments

Experiments were conducted on the WebShop and WikiHow task sets, using 100 and 702 tasks respectively. REMEMBERER's performance was evaluated across different initializations and training sets, showing significant success rate improvements over existing SOTA models.

Results

REMEMBERER achieved a 4% success rate increase on the WebShop task set and a 2% increase on the WikiHow task set. Ablation studies showed that long-term experience memory is more effective than short-term working memory.

Applications

REMEMBERER can be applied in scenarios requiring cross-task learning, such as intelligent assistants and automated customer service. Its ability to optimize decisions without frequent parameter tuning makes it advantageous in resource-constrained environments.

Limitations & Outlook

REMEMBERER may face memory capacity limitations when handling extremely complex tasks. Additionally, the initialization of experience memory may impact final outcomes, necessitating future research to optimize its structure and update strategy.

Plain Language Accessible to non-experts

Imagine a chef who constantly accumulates experience in cooking. Every time they cook, they note which steps were successful and which failed. The next time they cook a similar dish, they refer to these experiences to avoid past mistakes. REMEMBERER is like this chef, optimizing decisions through long-term memory rather than learning from scratch each time.

ELI14 Explained like you're 14

Imagine you're playing a complex game, and every time you fail a level, you note down why you failed. Next time you play, you avoid making the same mistakes. REMEMBERER is like this smart player, remembering past successes and failures to perform better in new tasks.

Glossary

Large Language Model (LLM)

A large-scale machine learning model capable of processing and generating natural language.

In REMEMBERER, the LLM is responsible for decision-making.

Reinforcement Learning (RL)

A machine learning method that optimizes strategies by interacting with the environment to receive rewards.

REMEMBERER uses RL to update experience memory.

Experience Memory

An external module that stores past interaction experiences for optimizing future decisions.

REMEMBERER stores successful and failed cases in experience memory.

RLEM

Reinforcement Learning with Experience Memory, optimizing LLM decisions by updating experience memory.

The core mechanism of REMEMBERER for self-evolution.

Semi-parametric

A hybrid model combining parametric and non-parametric methods.

REMEMBERER achieves semi-parametric learning through experience memory.

Open Questions Unanswered questions from this research

  • 1 How to optimize experience memory structure for larger task sets?
  • 2 How to integrate other machine learning methods to enhance REMEMBERER's performance?

Applications

Immediate Applications

Intelligent Assistants

REMEMBERER can be used in intelligent assistants to enhance interaction efficiency through long-term experience memory.

Long-term Vision

Automated Customer Service

Applying REMEMBERER in customer service systems can reduce human intervention and improve customer satisfaction.

Abstract

Inspired by the insights in cognitive science with respect to human memory and reasoning mechanism, a novel evolvable LLM-based (Large Language Model) agent framework is proposed as REMEMBERER. By equipping the LLM with a long-term experience memory, REMEMBERER is capable of exploiting the experiences from the past episodes even for different task goals, which excels an LLM-based agent with fixed exemplars or equipped with a transient working memory. We further introduce Reinforcement Learning with Experience Memory (RLEM) to update the memory. Thus, the whole system can learn from the experiences of both success and failure, and evolve its capability without fine-tuning the parameters of the LLM. In this way, the proposed REMEMBERER constitutes a semi-parametric RL agent. Extensive experiments are conducted on two RL task sets to evaluate the proposed framework. The average results with different initialization and training sets exceed the prior SOTA by 4% and 2% for the success rate on two task sets and demonstrate the superiority and robustness of REMEMBERER.

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