## 3 Methodology
### Evaluation Surveys
#### 3.3.1 Survey Q1: Opinion on the Use of 3D Sketching Tools  
Participants were asked to rate the following statements on a 5-point Likert scale: strongly agree, agree, neutral, disagree, and strongly disagree.  
_\"Regarding your experience using various 3D sketching tools in a virtual or augmented reality environment, please indicate your impressions:\"_  
1. If I were a designer (in architecture, engineering, or another field), I would like to use this tool frequently.
2. I find this system/tool unnecessary.
3. I believe the system is easy to use.
4. I think I would need the assistance of a technician to operate this system.
5. I find that the different drawing functions within the tool are well integrated.
6. I believe that most people would learn to use this system very quickly.
7. I think the system is uncomfortable to use.
8. I felt secure while using the system.
9. I had to learn many things before I could start using the system.
10. I felt irritated, stressed, and annoyed while using the tool.
11. Learning to sketch in 3D using virtual reality was mentally very demanding.
12. Sketching in 3D in virtual reality was physically very demanding.
13. Compared to sketching on paper with a pencil, this method of sketching in VR enhances the conceptual design process--I can better visualize it and redesign in real time.
14. It was satisfying to use the tool for the proposed objective.  
Figure 1: Apps for Drawing and Designing in VR (**a**). HMD for Drawing in a VR Environment (Meta Quest 2) and an AR Environment (Microsoft Hololens 2) (**b**).  
The formulation and selection of questions for this questionnaire were carefully based on specific criteria designed to accurately assess the user experience (UX) of sketching 3D drawings in virtual and augmented reality during the conceptual design phase. The goal is to evaluate how effectively these tools help students to achieve spatial understanding during the conceptual design phase. The questions are structured to measure the according 4 criteria:  
* Criteria 1. Ease of Use and Intuitiveness of the Tool (Usability). Questions related to ease of use (Q1_3, Q1_4, Q1_5, Q1_6 and Q1_9) were created to determine whether the selected tools were intuitive from the user's perspective. To effectively explore complex design elements such as scale, materials, and textures, it is essential that the tools do not pose additional barriers to students. These questions are crucial in determining whether the tools facilitate or hinder initial learning.
* Criteria 2. User Emotional and Psychological Experience. Questions addressing comfort (Q1_7, Q1_8), feelings of stress or irritation (Q1_10), and mental or physical demand (Q1_11, Q1_12) aim to explore the psychological and emotional dimensions experienced by students while interacting with immersive environments. As these are immersive environments, it is critical to evaluate whether the experience is emotionally positive or negative. Discomfort or stress could obstruct proper perception and exploration of the space, thereby reducing the effectiveness of the execution of the conceptual design phase.
* Criteria 3. Motivation and Technological Acceptance. Questions such as Q1_1, Q1_2, and Q1_14 directly assess the users' motivation and willingness to employ this technology in future professional contexts. It is important to identify if students perceive the tool as valuable and relevant to their development as designers, which is vital for its effective integration into the teaching and learning process.
* Criteria 4. Comparative Effectiveness vs. Traditional Techniques. Question Q1_13 specifically explores perceptions of comparative effectiveness between traditional methods (paper sketches) and the VR tool. It is essential to evaluate whether digital tools tangibly enhance spatial visualization and real-time redesign capabilities, both critical for deepening holistic understanding of space, materials, and lighting during the conceptual design phase.