## 4 Experimental Results and Discussion
### The Variance of Attention Index  
This study investigated the effect of a number of components on participants' EEG differences when they attempted to identify graphic symbol sets. Table 5 shows the average Attention Index values of the children with and without developmental delays identifying the 30 graphic symbol sets with various numbers of components. Table 5 demonstrates that the average Attention Index values for children with developmental delays identifying single- and multiple-component symbols were 60.22 (\(SD\) = 14.66) and 50.00 (\(SD\) = 7.29), respectively. The overall Attention Index for these participants was 55.41 (\(SD\) = 12.59). By contrast, the average Attention Index values for children without developmental delays identifying single- and multiple-component symbols were 50.33 (\(SD\) = 11.13) and 45.16 (\(SD\) = 7.76), respectively. The overall Attention Index for these participants was  
\begin{table}
\begin{tabular}{l c c c c c} \hline \hline
**Group** & \(N\) & \(M\) & \(SD\) & \(F\) & \(\eta^{2}\) \\ \hline DD—single-symbol & & 37.04 & 17.03 & & \\ multiple-symbol & 17 & 50.00 & 17.09 & & \\ \hline Peers—single-symbol & & 64.71 & 15.23 & & \\ multiple-symbol & 34 & 74.12 & 13.31 & & \\ \hline DD (All) & 17 & 43.14 & 17.81 & & \\ \hline Peers (All) & 34 & 69.41 & 14.87 & & \\ \hline Single-symbol (All) & 51 & 55.13 & 20.53 & & \\ \hline Multiple-symbol (All) & 51 & 66.40 & 18.31 & & \\ \hline \multicolumn{5}{c}{\({}^{\star}p<0.05\).} \\ \end{tabular}
\end{table}
Table 4: Success rates of PCS identification for children with and without developmental delays (DD) (by percentage).  
47.44 (\(SD\) = 9.60). In addition, the overall Attention Index values for the total population identifying single- and multiple-component symbols were 54.04 (\(SD\) = 13.19) and 46.59 (\(SD\) = 7.82), respectively. The research team conducted a two-way ANOVA to examine the effects of developmental status and the number of components on the Attention Index during graphic symbols identification. The results revealed a nonsignificant interaction between developmental status and a number of components (\(F\) = 0.686, \(p\) > 0.05), indicating no interaction between these two variables. Subsequently, this study separately examined the main effects of these two variables. The first one-way ANOVA revealed a statistical significance between developmental status and Attention Index (\(F\) = 5.845, \(p\) < 0.05), indicating that the two population groups had a significant difference in Attention Index. The mean numerical values also demonstrated that the children with developmental delays had significantly higher Attention Index values than those without developmental delays did. In addition, this study further explored the effect size of the developmental status variable on the Attention Index. The results revealed that the developmental status variable could explain 11.1% of the variance of Attention Index (\(\eta^{2}\) = 0.111). According to [PERSON] (1977), these two variables exhibited a moderate correlation with each other. By contrast, the second one-way ANOVA also revealed a statistical significance between a number of components and Attention Index (\(F\) = 6.386, \(p\)< 0.05), indicating the significant difference in Attention Index between single- and multiple-component symbols. The mean numerical values also demonstrated that the participants had a significantly higher Attention Index on single-component symbols than multiple-component symbols. The effect size between a number of components and Attention Index indicated that the number of components explained 12% of the variance of the index (\(\eta^{2}\) = 0.120), indicating a moderate correlation between the two variables.