## 2 Materials and Methods
### Experiment
#### 2.5.3 Measurements  
The NASA-TLX [30] questionnaire is used to measure the system's workload, and the SUS [22] questionnaire is used to measure the system's usability.  
The NASA-TLX is a widely used assessment tool for measuring the perceived workload of a specific task. It evaluates the workload in six subscales: mental demand, physical demand, temporal demand, performance, effort, and frustration. The specific contents of the six subscales are shown in Table 1. Users are asked to rate the perceived workload on each of these dimensions. The scores for the dimensions range from 0 (perfect) to 100 (failure) for performance and from 0 (low) to 100 (high) for the other five dimensions. For this assessment, the weighted measure involving pairwise comparisons between subscales is not included. The workload score is calculated as the average of the six subscales. Thus, the best workload score is 0 and the worst workload score is 100.  
The SUS survey is used to measure the usability of a system. The questionnaire requires users to rate 10 statements on a 7-point Likert scale, ranging from \"Strongly Disagree\" to \"Strongly Agree\". These statements cover various aspects of the system, such as complexity, consistency, and cumbersomenes. Like the NASA-TLX, the SUS is measured on a scale of 0 to 100. However, for SUS, 0 is the worst score, and 100 is the best score. The specific contents of 10 statements are shown in Table 2. Additionally, question 4 (\"I thought that I would need the support of a technical person to be able to use this system\") and question 10 (\"I needed to learn a lot of things before I could use this system\") relate to the learnability of the application, forming the learnability score and the other questions relate to the usability of the application, forming the usability score. The total score is the average of the learnability score and usability score.  
\begin{table}
\begin{tabular}{c c} \hline
**Measure** & **Explain** \\ \hline Mental Demand & How mentally demanding was the task? \\ Physical Demand & How physically demanding was the task? \\ Temporal Demand & How hurried or rushed was the pace of the task? \\ Performance & How successful were you in accomplishing what you were asked to do? \\ Effort & How hard did you have to work to accomplish your level of performance? \\ Frustration & How insecure, discouraged, irritated, stressed, and annoyed were you? \\ \hline \end{tabular}
\end{table}
Table 1: The measures of NASA-TLX and an explanation of the measures which used to measure different kinds of burdens imposed by the method.  
\begin{table}
\begin{tabular}{c c} \hline
**Number** & **Explain** \\ \hline
1 & I thought that I would like to use this system frequently \\
2 & I found the system unnecessarily complex \\
3 & I thought the system was easy to use \\
4 & I thought that I would need the support of a technical person to be able to use this system \\
5 & I found the various functions in this system were well integrated \\
6 & I thought that there was too much inconsistency in this system \\
7 & I would imagine that most people would learn to use this system very quickly \\
8 & I found the system very cumbersome to use \\
9 & I felt very confident using the system \\
10 & I needed to learn a lot of things before I could get going with this system \\ \hline \end{tabular}
\end{table}
Table 2: The statements of SUS and an explanation of the statements. The SUS scores reflect the overall usability.