## 3 Usibility Verification
### Results  
Figure 12(a) shows the score distribution of the survey participants' SUS evaluation results. As a result of SUS evaluation, 24 percent of the participants yielded scores under 60, the average minimum score to pass general tests, and 76 percent of the participants yielded scores over 60. This means that most of the participants were very satisfied with the usability of the content. Figure 12(b) shows the mean score for each question. The mean scores of the positive questions (Q1, 3, 5, 7, and 9) was 84.12, and that of the negative questions (Q2, 4, 6, 8, 10) was 62.02. The mean score of all questions was 73.36, which is higher than the average SUS score of 68. SUS scores are divided into seven adjective ratings. This content had more than 71.4 points and thus obtained a B grade (Excellent), which means that the system is \"useful\" [23; 24].  
\begin{table}
\begin{tabular}{c c c c c} \hline
**20–29 Years** & **30–39 Years** & **40–49 Years** & **50–59 Years** & **60–69 Years** \\ \hline
30 people & 30 people & 20 people & 10 people & 10 people \\ \hline \end{tabular}
\end{table}
Table 4: The age distribution of survey participants.  
\begin{table}
\begin{tabular}{c c} \hline
**Questions** & **Content** \\ \hline Q1 & I think that I would like to use this system frequently \\ Q2 & I found the system unnecessarily complex \\ Q3 & I thought the system was easy to use \\ Q4 & I think that I would need the support of a technical person to be able to use this system \\ Q5 & I found the various functions in this system were well integrated \\ Q6 & I thought there was too much inconsistency in this system \\ Q7 & I would imagine that most people would learn to use this system very quickly \\ Q8 & I found the system very awkward to use \\ Q9 & I felt very confident using the system \\ Q10 & I needed to learn a lot of things before I could get going with this system \\ \hline \end{tabular}
\end{table}
Table 2: SUS questions.  
\begin{table}
\begin{tabular}{c c c c c} \hline
**Total Number of** & **Average Age** & **Average Career** & **Maintenance** & **Experienced** \\
**Participants** & **Length** & **Operators** & **Operators** \\ \hline
100 people & 32.8 years & 4.7 years & 69 people & 21 people \\ \hline \end{tabular}
\end{table}
Table 3: Overall information of survey participants.  
Figure 14 shows the SUS evaluation results as a stacked graph. In terms of question 6 (uniformity), around 39% of participants responded with \"strongly disagree\". Therefore, it was confirmed that the content lacked consistency. In addition, it is necessary to improve the convenience of use, as around 35% of participants responded with \"strongly disagree\" to question 8 (convenience). In contrast, roughly 70% of participants responded with \"strongly agree\" to question 3 (simplicity). This confirms that the content is intuitively structured. Moreover, approximately 57% of participants responded with \"strongly agree\" to questions 5 (integration) and 7 (learnability). This indicates that this content has a well-organized user interface, making it easy to perform training.  
According to the results, the usability verification shows that most users were satisfied with the content. These results also demonstrate that the content is convenient to use and suitable for railway maintenance training.