## 3 Results
### The Fixation Rate for the Four Proficiency Levels  
The fixation rate for system-malfunction and system-limit failures at four proficiency levels is presented in Table 5. For facilitating visual observation, Figure 6 illustrates the data of fixation rate and SD from Table 5.  
The statistical analysis results indicated that at various proficiency levels, the impact of system-malfunction and system-limit failures on fixation rate was not significant (\(p\) = 0.290 \(>\) 0.05, F = 1.144). In terms of numerical values, for all proficiency levels except level 1 (inexperienced), the fixation rate for system-malfunction failure was lower than that for system-limit failure, and the ratio between the two varied as follows: 1.056, 0.938, 0.824, and 0.887 at proficiency levels 1 to 4, respectively.  
In the case of system-malfunction failures, proficiency level had a significant impact on the fixation rate required to resolve the failures (\(p\) < 0.05). As proficiency level increased, the fixation rate for resolving the failures exhibited a pattern of increase-decrease-increase. The ratio of fixation rate between lower proficiency level and adjacent higher proficiency level was 0.941, 1.062, 0.906, respectively.  
In the case of system-limit failures, as proficiency level increased, the fixation rate for resolving the failures significantly increased (\(p\) < 0.05). The ratio of fixation rate between lower proficiency level and adjacent higher proficiency level showed a monotonic increase: 0.836, 0.933, 0.975, respectively.  
The fixation rate increased with higher proficiency level, indicating that as proficiency increased, operators were able to attend to more points of interest within a given time. They could obtain effective information in shorter fixation durations and then shift their attention to the next area, exhibiting a more balanced distribution of attention.  
Figure 6: The fixation rate for system-malfunction and system-limit failures at four proficiency levels.  
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Proficiency Level** & **Failure Type** & **Fixation Rate** & **SD** & **RML-FR 1** & **MProf-FR 2** & **LProf-FR 3** \\ \hline
1. Inexperienced & Malfun & 1.622 & 0.568 & 1.056 & 0.941 & 0.836 \\  & Limit & 1.536 & 0.623 & — & — & — \\
2. Low Proficiency & Malfun & 1.724 & 0.609 & 0.938 & 1.062 & 0.933 \\  & Limit & 1.838 & 0.659 & — & — & — \\
3. Moderate Proficiency & Malfun & 1.624 & 0.526 & 0.824 & 0.906 & 0.975 \\  & Limit & 1.971 & 0.726 & — & — & — \\
4. High Proficiency & Malfun & 1.793 & 0.657 & 0.887 & — & — \\  & Limit & 2.021 & 0.736 & — & — & — \\ \hline \hline \end{tabular}  
* \({}^{1}\) RML-FR stands for the ratio of system-malfunction failure fixation rate to system-limit failure fixation rate. 2
* \({}^{2}\) MProf-FR stands for the ratio of fixation rate between low proficiency level and the adjacent higher proficiency level in the case of system-malfunction failure. 3
* LProf-FR stands for the ratio of fixation rate between low proficiency level and the adjacent higher proficiency level in the case of system-limit failure.  
\end{table}
Table 5: The fixation rate for system-malfunction and system-limit failures at four proficiency levels.