## 4 Experimental Results and Discussion  
### Success Rates of AAC Graphic Symbols Identification  
This study aimed to investigate the effect of a number of symbol components on graphic symbols recognition and learning outcomes. Table 4 shows the success rates of the children with and without developmental delays identifying the 30 graphic symbol sets with various numbers of components. Table 4 demonstrates that the average success rates for children with developmental delays identifying single- and multiple-component symbols were 37.04% (\(SD=17.03\%\)) and 50.00% (\(SD=17.09\%\)), respectively. The overall success rate for these participants was 43.14% (\(SD=17.81\%\)). By contrast, the average success rates for children without developmental delays identifying single and multiple-component symbols were 64.71% (\(SD\) = 15.23%) and 74.12% (\(SD\) = 13.31%), respectively. The overall success rate for these participants was 69.41% (\(SD\) = 14.87%). In addition, the overall success rates for the total population identifying single- and multiple-component symbols were 55.13% (\(SD\) = 20.53%) and 66.40% (\(SD\) = 18.31%), respectively. This study conducted a two-way ANOVA to examine the effects of developmental status (i.e., children with developmental delays and peers) and a number of components (i.e., single- and multiple-component symbols) on the success rate of graphic symbols identification. The results revealed a nonsignificant interaction between developmental status and the number of components (\(F\) = 0.154, \(p\)\(>\)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 statistically significant interaction between developmental status and the success rate of graphic symbols identification (\(F\) = 32.656, \(p\) \(<\) 0.05), indicating that the two population groups had a significant difference in graphic symbols identification. The mean numerical values also demonstrated that the children without developmental delays had a significantly higher success rate than did those with developmental delays. In addition, this study further explored the effect size of the developmental status variable on the success rate of graphic symbols identification. The results revealed that the developmental status variable could explain 41% of the variance of the success rate (\(\eta^{2}\) = 0.410). These two variables exhibited a strong correlation to each other [51]. By contrast, the second one-way ANOVA also revealed a statistical significance between a number of components and the success rate of graphic symbols identification (\(F\) = 6.096, \(p\)\(<\) 0.05), indicating a significant difference for success rates between single- and multiple-component symbols. The mean numerical values also demonstrated that the participants had a significantly higher success rate at identifying multiple-component symbols than single-component symbols. The effect sizes for a number of components and success rates of graphic symbols identification indicated that the number of components explained 11.5% of the variance of the success rate (\(\eta^{2}\) = 0.115), indicating a moderate correlation between the two variables.