## 3 Materials and Methods: Eye-Tracking Experiment
### Data Analysis and Result
#### 3.5.2 Analysis of the Sight-Focused Area  
The main purpose of this step is to investigate the priority level of attention given to different areas, the trajectory of the user fixation points as it switches between areas, and the position and sequence of the fixation points when the subjects observe the experimental materials of the coating scheme. The digital serial number in the fixation point indicates the order of eye-tracking when the user observes the experimental materials. The line between the two fixation points near the serial number represents the behavioral process of the user's vision switching from one fixation point to another. The size of the circle indicates the length of time during which the picture material was observed. The longer the fixation time was, the larger the circle is. The experimental results are shown in Figure 5. The images of the eye trajectories for each of the four experimental groups are clustered and grouped in order to observe and analyze the characteristics of the subjects' eye trajectory changes. In Experiment 1 (scale of logo and machine tool model), it was found that when the subjects observed the experimental materials, the fixation point numbers of A-2, A-3, and A-4 with the larger-scale logo and machine tool model, the gaze was more forward and the fixation point was smaller, indicating a short fixation time. This reflects that the identified elements of a larger scale can attract the users' attention faster, and the priority of fixation is higher. At the same time, due to the larger and clearer font, it takes less time for the user to identify the information, and the ability to identify information is stronger. The designs of the logo and model size within these ranges can more effectively attract people's attention and transmit information. In Experiment 2 (typographic position of the logo and machine type), the layout schemes B-1, B-2, and B-3, where the logo and machine tool model are coated on both sides of the machine tool bed, respectively, received better feedback from the users. Schemes B-2 and B-3, in which the two elements are coated on the upper sides of the bed, respectively, were viewed earlier, with smaller fixation points and a shorter time. In addition, scheme B-3, with the logo coated on the right side and the model number coated on the left side of the bed, is more in line with the habit of reading from left to right, and it received the best feedback from the subjects. Therefore, when optimizing the design scheme, we can refer to the experimental analysis results and the layout of the experimental picture B-3. In Experiment 3 (color coating scheme of the machine tool), the first fixation point of the experimental picture was located in the central observation window of the picture, followed, in turn, by the scanning of the logo and machine tool models, the content of which could arouse the interest of the subjects and cause the subjects to fixate for a long time. Then, the bed and the base were briefly scanned in turn. This indicates that the subjects' observation of the coating design scheme of the machine tools stared with the observation window in the center of the machine tool. The content of the logo was more visually attractive to the subjects, while the bed and base were less attractive. The attractiveness of Schemes C-1 and C-4 was greater than that of the other schemes in the group, which indicates that these two coating design schemes are more likely to attract the user's attention and observation interest, and the information conveyed is clearer, which can aid in the optimization of the design scheme. In Experiment 4 (color matching scheme of the machine tools), when the subjects observed Schemes D-1 and D-3, with a stronger color contrast, they showed larger fixation points, which means a longer fixation time and greater interest. The elements that mainly attracted the user's first sight were usually the logo, followed by the text, the more complex  
Figure 5: Illustration of user’s sight trajectory.