Can Advanced LLMs Coach Smaller LLMs? Knowledge Distillation for Goal-Oriented Dialogs
Tong Wang, K. Sudhir, Dat Hong
Published: 2024/8/13
Abstract
Enterprises deploying LLMs for goal-oriented dialogs, such as customer service, face a critical trade-off between performance, control, and cost. Proprietary models like GPT-4 offer strong performance but are costly and cannot be self-hosted, raising security and privacy concerns. Open-source alternatives offer flexibility and lower token costs but lag in performance. We introduce Guidance Elicitation and Retrieval (GER), a prompt-based knowledge distillation framework where a high-performance teacher LLM coaches a lower-performance student without modifying the student's parameters. GER extracts tactical guidance for a wide range of dialog scenarios from the teacher and stores these scenario-guidance pairs in a structured library. At inference time, the student retrieves the relevant guidance and integrates it into its prompt. While GER training can be bootstrapped entirely with synthetic data, its modular design lets it seamlessly augment the synthetic data with human conversational logs. In addition, the modular design enables easy auditing and updating of the guidance library as new scenarios and constraints emerge. Experiments show GER's guidance-based coaching outperforms both example output based fine-tuning and non-customized guidance baselines, and generalizes across other contexts and student models. The GER framework is potentially extensible to coach human service agents.