An LLM-Based Motivation-Aware Framework For AI Coaching For Behaviour Change

Digital health coaches can deliver affordable, accessible behaviour coaching to broad populations. While prior research in motivational interviewing (MI) systems has emphasised emotional support strategies, it has overlooked the role of goal-setting behaviours in achieving successful coaching outcomes. We propose a coaching framework that provides motivational support for ambiguous clients while employing planning-focused strategies for action-ready clients. The user study evaluated our framework against a baseline system for promoting physical activity. Results showed significant increases in users’ readiness to change after interacting with our motivational coaching chatbots. Participants perceived our agent as more adherent to MI principles and more effective at planning than the baseline. Qualitative analysis revealed that users who agreed with the agent on a change plan experienced the greatest increases in intrinsic motivation. Finally, we examine how these findings align with expert opinions that informed our system design principles and discuss implications for LLM-based health coaching.