## 6 Results (Study 2)
### Phase 1: Performance Differences Between Age Groups on FOD--Advanced Combination 3  
An independent-samples \(t\)-test was conducted for each simulator performance variable using age group as the independent variable. The results for all 13 \(t\)-tests can be found in Table 5. The variables significant at an alpha level of 0.0038 were average target E reaction time, \(t\)(52.778) = 4.081, \(p\) < 0.001; standard deviation of target E reaction time, \(t\)(52.781) = 3.325, \(p\) < 0.002; number of target E extra presses, \(t\)(50.267) = 4.512, \(p\) < 0.001; \begin{table}
\begin{tabular}{c c c c c c c c} \hline \hline \multirow{2}{*}{**Performance Variables**} & \multicolumn{5}{c}{**Teens (N = 21)**} & \multicolumn{5}{c}{**Seniors (N = 34)**} \\  & \(M\) & \(SD\) & **Min** & **Max** & \(M\) & \(SD\) & **Min** & **Max** \\ \hline Percent of target Es detected & 97.8 & 3.5 & 89.3 & 100.0 & 93.9 & 7.7 & 71.4 & 100.0 \\ \hline Average target E reaction time (s) & 1.4 & 0.2 & 1.3 & 1.9 & 1.7 & 0.3 & 1.1 & 2.1 \\ \hline SD of target E reaction time (s) & 0.4 & 0.1 & 0.2 & 0.6 & 0.5 & 0.2 & 0.2 & 0.8 \\ \hline Number of target E extra presses & 0.2 & 0.4 & 0.0 & 1.0 & 1.0 1 & 0.8 1 & 0.0 & 3.0 \\ \hline Number of distractor E presses & 0.6 & 1.0 & 0.0 & 3.0 & 1.3 & 1.5 & 0.0 & 5.0 \\ \hline Percent of brake lights detected & 96.8 & 4.2 & 85.4 & 100.0 & 92.0 & 9.2 & 65.5 & 100.0 \\ \hline Average brake reaction time (s) & 1.2 & 0.2 & 1.0 & 1.6 & 1.4 & 0.2 & 0.8 & 1.7 \\ \hline SD of brake reaction time (s) & 0.3 & 0.1 & 0.2 & 0.6 & 0.4 & 0.1 & 0.2 & 0.6 \\ \hline Number of brake extra presses & 0.9 & 1.9 & 0.0 & 8.0 & 1.6 & 1.7 & 0.0 & 9.0 \\ \hline Percent of time in lane & 99.8 & 1.1 & 95.0 & 100.0 & 99.8 & 1.0 & 95.9 & 100.0 \\ \hline Number of lane excursions & 0.1 & 0.4 & 0.0 & 2.0 & 0.1 & 0.4 & 0.0 & 2.0 \\ \hline Average speed (mph) & 28.8 & 5.0 & 17.0 & 35.1 & 27.7 & 8.6 & 8.2 & 44.9 \\ \hline Variability of speed (mph) & 3.7 & 1.6 & 1.9 & 7.7 & 4.4 & 1.7 & 1.7 & 9.2 \\ \hline \hline \end{tabular}  
* Note: This statistic used a sample size of 33 due to an error with one participant’s data.  
\end{table} 
Table 4: Descriptive statistics for the performance variables in FOD—Advanced combination 3.  
and standard deviation of brake reaction time, \(t(53)=4.008\), \(p<0.001\). The average target E reaction time was lower for teens [\(M=1.448\), \(SD=0.154\)] compared to seniors [\(M=1.681\), \(SD=0.269\)]. The standard deviation of target E reaction time was greater for seniors [\(M=0.527\), \(SD=0.166\)] in comparison to teens [\(M=0.410\), \(SD=0.095\)]. The number of target extra presses for seniors [\(M=1.030\), \(SD=0.847\)] was greater relative to teens [\(M=0.238\), \(SD=0.436\)]. The standard deviation of brake reaction time was greater for seniors [\(M=0.440\), \(SD=0.097\)] than for teens [\(M=0.334\), \(SD=0.093\)]. Only these four variables were used for Phase 2's LDA analysis. It deserves noting that there were three variables that approached significance at an alpha level of 0.01 (see Table 5). Although these variables did not quite reach the threshold, the results were reported at an alpha level of 0.05. The variables were percent of target Es detected, \(t(49.505)=-2.551\), \(p=0.014\); percent of brake lights detected, \(t(49.943)=-2.622\), \(p=0.012\); and average brake reaction time, \(t(53)=2.595\), \(p=0.012\). Specifically, teens [\(M=97.789\), \(SD=3.477\)] performed better on identifying the percent of target Es detected compared to seniors [\(M=93.908\), \(SD=7.692\)]. Similarly, when comparing the percent of brake lights detected, teens [\(M=96.797\), \(SD=4.246\)] responded to a greater percentage compared to seniors [\(M=92.010\), \(SD=9.175\)]. The average brake reaction time was longer for seniors [\(M=1.358\), \(SD=0.169\)] relative to teens [\(M=1.240\), \(SD=0.158\)]. When interpreting the results of the \(t\)-tests, not only should the test statistics and the significance be evaluated, but also the effect size.