## 5 Results
### The Effectiveness of PBL Influenced by Learners' Use of GAI  
The course adopts a cumulative assessment system, with the content of the last lesson as an important part of the final grade that has a high weight and is directly related to the learner's final grade. At the same time, after a series of learning and practice tasks, learners achieve a high level of proficiency and stability in the use of course content, operational processes, and learning tools in the final lesson. This increased proficiency helps to reduce the experimental errors caused by rusty skills or understanding bias, making the collected data on learner behavior more accurate and reliable. Consequently, the third set of analyses concentrated on the distribution and categories of the GAI-related behaviors demonstrated by learners across the diverse performance groups (high, medium, and low) in relation to the PBL task conducted during the concluding session. Insights into the behavioral patterns and their correlation with learning effectiveness are summarized as follows:  
Table 3 presents the following distribution of GAI behaviors among performance groups:  
1. Differentiated behavioral patterns * _High- and Medium-Performance Groups:_ These groups demonstrated consistent and exploratory use of GAI during the mid-stages of the PBL task. Their behaviors often involved complex problem-solving, iterative dialogues, and strategic questioning. They engaged in more advanced interactions that blended exploratory and functional use, showcasing adaptability and strategic planning; * _Low-Performance Group:_ This group's deep and exploratory GAI usage was concentrated in the early stages but diminished as the project progressed. Their behaviors suggested challenges in maintaining effective engagement, particularly during mid- and late-stage PBL tasks. 2. Behavioral trends across stages as depicted in the Sankey diagram in Figure 11 * _Pre- and Mid-Stages:_ All performance groups utilized GAI relatively evenly during these periods, though high-performing students excelled in exploratory interactions;* _Late Stage_: High-performing learners exhibited sustained interaction with GAI, often engaging in iterative dialogues and in-depth content creation, while low-performing learners showed a marked decline in engagement and critical questioning behaviors. We can conclude the following characteristics of high-performance learners' GAI usage:  
* _Effective problem definition and retrieval skills_: High performers excelled in defining problems precisely, employing appropriate keywords, and generating innovative, task-relevant queries. These skills enhanced their ability to extract meaningful insights from GAI;
* _Iterative dialogues and effort investment_: This group engaged in more dialogue rounds with GAI, reflecting their willingness to explore ideas comprehensively. They demonstrated a balance between the quantity and quality of interactions, maximizing the tool's potential for detailed feedback and refinement. The following challenges were faced by low-performance learners:
* _Deficiencies in problem definition_: Low performers struggled with framing effective queries, which impacted the relevance and utility of GAI responses;
* _Reduced engagement over time_: While their early-stage usage involved deep interactions, they were less consistent in maintaining meaningful dialogues during subsequent project stages. The experiment highlights the influence of GAI on learning effectiveness, with notable variations across performance groups:  
Figure 11: Sankey diagram illustrating the distribution of behaviours among different performance groups at various stages of learning.