Abstract
The rise of generative artificial intelligence (GAI) applications, epitomized by ChatGPT, has reshaped design processes by enhancing idea generation and conceptual depth for designers. However, the facilitating effects on novice designers' thinking remain uncertain, particularly in the context of sustainable service concept generation. This study examines these impacts of ChatGPT on design thinking process and outcomes through controlled experiments with 36 novice designers with ChatGPT, Tiangong AI, and no tools under a sustainable service design task. Through the protocol analysis, this study visualizes the design thinking by network-based cognitive maps, then evaluates design outcomes and systematically analyzes characteristics of design thinking development under different tool interventions. Findings indicate that ChatGPT enhances design concept novelty and systematicity but has limited impact on originality and sustainability. Furthermore, ChatGPT plays an active role in fostering thinking divergence and fluency, especially in providing relevant guides for developed ideas and accelerating the evaluation and creation process. The network-based cognitive maps reveal distinct shifts and styles influenced by ChatGPT, providing references for novice designers using such tools to enhance inspiration and design fluency, and also effectively employ diverse tools during specific concept generation stage. The study also provides insights for enhancing the relevance of educational curricula and enabling bottom-up sustainable service innovations.