Prompted LLMs as Chatbot Modules for Long Open-domain Conversation
Gibbeum Lee, Volker Hartmann, Jongho Park, Dimitris Papailiopoulos, Kangwook Lee
TL;DR
The paper addresses the high cost and rigidity of fine-tuning large language models for open-domain dialogue. It introduces MPC, a modular prompted chatbot that uses separate LLM-driven modules for utterance clarification, memory processing, generation, and dialogue summarization, supplemented by a Dense Passage Retriever memory store and CoT-inspired reasoning. Through extensive human evaluations, MPC with pre-trained LLMs matches or surpasses fine-tuned BlenderBot 3 in long-form conversations, demonstrating strong long-term consistency and engagement without fine-tuning. The work underscores the potential of modular prompting and memory augmentation to build flexible, domain-agnostic chatbots, while acknowledging limitations in efficiency and language scope.
Abstract
In this paper, we propose MPC (Modular Prompted Chatbot), a new approach for creating high-quality conversational agents without the need for fine-tuning. Our method utilizes pre-trained large language models (LLMs) as individual modules for long-term consistency and flexibility, by using techniques such as few-shot prompting, chain-of-thought (CoT), and external memory. Our human evaluation results show that MPC is on par with fine-tuned chatbot models in open-domain conversations, making it an effective solution for creating consistent and engaging chatbots.
