## 4 Results
### Correlation Analysis  
#### 4.3.1 Correlation Among STAI Subscales  
As shown in Table 4 and Figure 7, in Stage 1, the correlations among the STAI subscales were generally high. For example, the correlation between STAI-S and STAI-T was 0.669, and the correlation between STAI-T and the total STAI score was 0.929, indicating a strong linear relationship among the subscale scores before the intervention (encouragement prompt system). However, after the intervention, most correlation coefficients decreased. For instance, the correlation between STAI-S and STAI-T dropped from 0.669 to 0.509, and the correlation between STAI-T and the total STAI score decreased from 0.929 to 0.910. This change may suggest that the intervention partially weakened the correlations among different dimensions of anxiety.  
Regarding the correlations among the STAI-C subscales, the correlation between STAI-C_S and STAI-C_T in Stage 1 was relatively low at 0.211, indicating a weak association between children's state anxiety and trait anxiety before the intervention. In Stage 2, this correlation increased to 0.257, suggesting a slight enhancement of the relationship between these two dimensions after the intervention. The correlation between STAI-C S and the total STAI-C score increased slightly from 0.716 to 0.743, indicating that the association  
\begin{table}
\begin{tabular}{c c c c c c c c} \hline
**STAGE 1** & **STAI-S** & **STAI-T** & **STAI** & **STAI-C S** & **STAI-C T** & **STAI-C** & **STAI-P** \\ \hline STAI-S & 1.0 & 0.669 & 0.897 & 0.300 & 0.357 & 0.424 & 0.445 \\ STAI-T & 0.669 & 1.0 & 0.929 & 0.349 & 0.270 & 0.390 & 0.429 \\ STAI & 0.897 & 0.929 & 1.0 & 0.357 & 0.338 & 0.444 & 0.477 \\ STAI-C S & 0.300 & 0.349 & 0.357 & 1.0 & 0.211 & 0.716 & 0.435 \\ STAI-C T & 0.357 & 0.270 & 0.338 & 0.211 & 1.0 & 0.833 & 0.141 \\ STAI-C & 0.424 & 0.390 & 0.444 & 0.716 & 0.833 & 1.0 & 0.347 \\ STAI-P & 0.445 & 0.429 & 0.477 & 0.435 & 0.141 & 0.347 & 1.0 \\ \hline
**STAGE 2** & **STAI-S** & **STAI-T** & **STAI** & **STAI-C S** & **STAI-C T** & **STAI-C** & **STAI-P** \\ \hline STAI-S & 1.0 & 0.509 & 0.819 & 0.167 & 0.095 & 0.160 & 0.417 \\ STAI-T & 0.509 & 1.0 & 0.910 & 0.326 & 0.277 & 0.377 & 0.407 \\ STAI & 0.819 & 0.910 & 1.0 & 0.298 & 0.231 & 0.328 & 0.471 \\ STAI-C S & 0.167 & 0.326 & 0.298 & 1.0 & 0.257 & 0.743 & 0.344 \\ STAI-C T & 0.095 & 0.277 & 0.231 & 0.257 & 1.0 & 0.837 & 0.304 \\ STAI-C & 0.160 & 0.377 & 0.328 & 0.743 & 0.837 & 1.0 & 0.405 \\ STAI-P & 0.417 & 0.407 & 0.471 & 0.344 & 0.304 & 0.405 & 1.0 \\ \hline \end{tabular}
\end{table}
Table 4: Correlation among stress scales (STAI, STAI-C, and STAI-P).  
Figure 7: Correlation Matrix between STAI, STAI-C, and STAI-P: (**a**) Stage 1 (stress detection, stress information feedback); (**b**) Stage 2 (stress detection, stress information feedback, and encouragement prompts).  
between trait anxiety and overall anxiety strengthened post-intervention. Additionally, the correlation between STAI-P and STAI-C S decreased from 0.435 to 0.344, while the correlation with STAI-C T increased significantly from 0.141 to 0.304, and the correlation with the total STAI-C score rose from 0.347 to 0.405. This suggests that parents' perception of children's stress became less correlated with children's state anxiety but had a more pronounced impact on their trait anxiety.  
After the intervention, many correlation coefficients showed a decline, particularly between the total STAI score and other subscales. This may reflect the intervention's effect in independently improving different dimensions of anxiety, thereby reducing the interdependence among the scales.