## 6 Conclusions and Discussion  
In the context of the rapid development of GAI and other large-scale models, these technologies have become central to academic and practical discussions, particularly regarding their application in education. Numerous studies indicate that the rational application of GAI can enhance both teaching efficiency and learning quality, yielding positive outcomes for education [36]. Despite the rapid technological advancements, particularly with the widespread use of large language models, some countries have introduced policies banning GAI in academic assessments to prevent unfair advantages and dependency [37]. Hence, how to leverage GAI effectively in education remains a key topic for further exploration. We therefore analyze the relationship between GAI and PBL as a way of answering the first question: Can GAI facilitate PBL learning and, at the same time, can PBL provide a research avenue for GAI? To answer this query, this study innovatively combined GAI with PBL by designing and building a GAI-PBL online learning platform. By conducting a one-year experimental study on this platform, we not only verified the feasibility of GAI technology in assisting PBL learning and solving the existing problems of PBL but also revealed the unique value of the PBL teaching model in exploring the effectiveness of the application of GAI technology--it provides a fruitful research framework and paradigm. Specifically, the characteristics of PBL, such as information integration and cooperation and communication, provide a rich practical scenario for evaluating the mechanism, effect, and optimization path of GAI technology in the learning process. Our GAI-PBL platform development reveals several key alignments between the functional characteristics of GAI and the learning methods promoted by PBL. For instance, PBL emphasizes communication among students and GAI, as a conversational model, provides learners with opportunities for dialogue, making it possible for students to work together virtually. By operating multiple GAI models simultaneously, learners can form a PBL group, enabling them to collaborate on project-based tasks. Furthermore, the platform overcomes many of PBL's traditional limitations, thereby enhancing its potential for educational research. Regarding the second question of how GAI influences students' learning behaviors, cognitive skills, and learning outcomes, our study identifies several complex, interrelated phenomena. These findings underscore the potential value of GAI as a supportive tool in learning but also highlight some challenges and risks. Firstly, the introduction of GAI has significantly transformed the learning process. Learners naturally incorporate the use of GAI into the learning process, producing a series of behavioral sequences. Learners are increasingly inclined to ask questions with the help of GAI, often after engaging in deeper analysis and contextualization. This suggests that GAI facilitates deep learning. Additionally, GAI stimulates learners' critical thinking, prompting them to evaluate whether the answers provided meet their learning needs. In the context of PBL, direct access to external knowledge enriches students' understanding and fosters new insights [38]. GAI's immediate feedback and vast knowledge base allow learners to quickly explore diverse perspectives, promoting the development of critical thinking. Learners are encouraged to question, analyze, and assess the reliability and relevance of information, which is crucial in today's information-rich environment. This process is vital for developing independent thinking and problem-solving abilities. Furthermore, the impact of GAI on students' cognitive processes is profound. As the learning cycle progresses, students' trust in GAI gradually intensifies. Compared to the first semester, students in the second semester exhibited a reduced tendency to deeply consider and verify the answers provided by GAI upon receipt.