## 3 Research Execution and Analysis
### Dimension Reduction and Naming of Usability Indicators  
Before conducting an Exploratory Factor Analysis (EFA), it is essential to assess the validity and reliability of the data obtained from the online survey to ensure their suitability. A Kaiser-Meyer-Olkin (KMO) value greater than 0.7 and [PERSON]'s test of sphericity significance value less than 0.05 indicate good validity [82]. A Cronbach's alpha coefficient between 0.7 and 0.95 suggests good reliability of the scale [85; 86]. Consequently, in this study, we calculated the KMO value, [PERSON]'s test of sphericity, and Cronbach's alpha coefficient for the survey indicators using SPSS 27.0, as shown in Table 4. The results yielded a KMO of 0.923, [PERSON]'s test of sphericity significance < 0.05, and a Cronbach's alpha of 0.923. These results confirmed that the survey data were both reliable and valid, making it suitable for EFA analysis. In the Exploratory Factor Analysis (EFA), the criteria for factor extraction were set such that only factors with eigenvalues (\(\lambda\)) greater than 1 were considered, and any factor composed solely of a single item was excluded. If the loading difference between two items on the same factor was less than 0.05, one of the items was removed and the analysis was re-run. Items associated with a factor with a community of less than 0.4 or a maximum loading of less than 0.35 were also excluded [87]. After multiple rounds of selection and rotation, four common factors with eigenvalues greater than 1 were ultimately identified, and 24 indicators related to the usability of medical websites were retained. The aforementioned methodology determined the proportion of each factor in the total variance, as shown in Table 5. The scree plot illustrated in Figure 2 further elucidates the contribution of each factor to the total variance. The rotated component matrix in Table 6 provides a detailed depiction of the correlations between the extracted factors (such as B1, B2, etc. ), and the indicators (such as Effectiveness, Convenience, etc. ). \begin{table}
\begin{tabular}{c c c} \hline \hline  & **Test** & **Test Value** \\ \hline KMO & & 0.924 \\ \hline \multirow{4}{*}{Bartlett’s} & Approximate Chi-Square & 4255.067 \\ \cline{2-3}  & Degrees of Freedom (df) & 276 \\ \cline{2-3}  & Significance & 0.00 \\ \hline Cronbach’s Alpha & & 0.921 \\ \hline \hline \end{tabular}
\end{table} 
Table 4: Results of KMO and Bartlett’s test result. Figure 2: Scree plot. \begin{table}
\begin{tabular}{c c c c c c c c c c} \hline \hline  & & \multicolumn{6}{c}{**Total Variance Explained**} \\ \hline \multirow{3}{*}{**Element**} & \multicolumn{6}{c}{**Initial Eigenvalues**} & \multicolumn{3}{c}{**Sum of Squared Loadings for Extraction**} & \multicolumn{3}{c}{**Rotated Sum of Squared Loadings**} \\ \cline{2-10}  & \multirow{2}{*}{**Total**} & **Percentage of Variance** & **Percentage of Variance** & **Percentage of Variance** & **Percentage of Variance** & **Percentage of Variance** & **Percentage of Variance** & **Percentage of Variance** \\  & & **Explained** & **Explained** & **Explained** & **Explained** & **Explained** & **Explained** & **Explained** \\ \hline  
\hline \end{tabular}
\end{table} 
Table 5: _Cont._Based on the results of the rotated component matrix and the characteristics of the indicators in each dimension, we denoted the reduced common factors as follows:  
The first group of common factors, B1, includes the following indicators: Effectiveness, Convenience, Usability, Efficiency, Errors, Satisfaction, and Learnability. These indicators primarily measure the basic experience and efficacy of users when using products or services. They relate to the fundamental functions of the product and are, thus, named Basic Performance. The second group of common factors, B2, comprises the following indicators: Feedback, Navigation, Screen Design and Layout, Consistency, User-Centered, and Interactivity. These indicators focus on the quality of product design and aspects of user interaction and are, therefore, named Design and Interface.