## 3 Methodology
### Design and Procedure  
For quantitative analysis, firstly, descriptive statistics were used; however, to reveal the crucial differences between groups of secondary school students in sensor-based learning outcomes, creativity, and intrinsic relevance in traditional STEM and STEAM engineering courses, clustering analysis was carefully applied [81]. Regarding questions related to students' learning outcomes (Q1-Q5), to create the questionnaire, the authors used general sensor-based knowledge, including the Arduino ecosystem, programming and electronics fundamentals, libraries, and communication features. Moreover, the questions assessed whether secondary school students possessed the ability to think critically and logically, to clearly and concisely identify the most important elements of a problem, to develop possible solutions, and to apply new crucial sensor-based knowledge in practical and versatile real-world applications. For the intrinsic relevance evaluation, the ARCS model of learning motivation was used and carefully modified in Q6-Q10 [82]. The ARCS model includes four factors that could effectively help to enhance students' learning motivations and interests, namely \"attention\", \"relevance\", \"confidence\", and \"satisfaction.\" The ARCS motivation model has been widely applied in the literature for a variety of quantitative evaluation works [83; 84; 85; 86; 87]. Nevertheless, previous studies mainly used the ARCS model to reveal the key factors in the learning motivations of students or the relationship between factors. The presented research only highlighted relevance as a key factor to be assessed. According to the relevance factor, a sensor-based course and its learning topics aim to enhance students' interest in problem-solving, designing, and programming, making students immerse themselves in learning activities, especially in mathematics, science, technology, and the arts. Learning topics can help cultivate self-learning capabilities and enhance pleasant learning experiences related to the course contents with useful skills and information. Moreover, the relevance aspect was designed for this research questionnaire in order to evaluate students' self \begin{table}
\begin{tabular}{l l} \hline \hline
**General Sensor-Based Knowledge (Directed to Tutors)** & **Short Name** \\ \hline The student is familiar with basic sensor-based knowledge, including Arduino microprocessors, digital & Q1 \\ communication, sensors, and actuators. & Q2 \\ The student has no significant difficulty programming the basic electronic parts. & Q3 \\ The student is able to design, test, and modify the electronic circuits with limited supervision and instructions. & Q4 \\ The student is able to transfer knowledge and apply skills across multiple contexts for real-world challenges. & Q5 \\ The student is able to communicate and collaborate clearly on intellectual and emotional levels to share ideas, & Q6 \\ gain main insights into the problem, and identify solutions effectively. & \\ \hline \hline
**Intrinsic relevance (Directed to Students)** & \\ \hline The course is interesting in its problem-solving, designing, and programming practices. & Q6 \\ The course let me feel more related to the contents with useful skills and information. & Q7 \\ I learned new things about communication and collaboration with my colleagues. & Q8 \\ I improved my interest in mathematics, science, and technology. & Q9 \\ I improved my appreciation for the arts. & Q10 \\ \hline
**Creativity (Directed to Students)** & \\ \hline I enjoyed learning, while the hands-on work felt automatic and effortless. & Q11 \\ If I get stuck on a problem, I look for clues in my surroundings. & Q12 \\ The course boosted my imagination for potential solutions to a problem. & Q13 \\ Thinking about more than one idea at the same time can lead to a new understanding. & Q14 \\ In this course, I tried to generate as many ideas as possible. & Q15 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: The anonymous questionnaire directed to students and tutors.