## 5 Discussion  
### Characteristics of Wake-Up Tasks  
_normal_task_ is the most casual task type. _normal_task_ is the easiest and causes the lowest task load. The task completion time of _normal_task_ was the shortest (14 s), and also the number of the snooze uses was the lowest (0.155 times) among the tasks. Such a low level of the task load possibly leads users to use _normal_task_ frequently and casually in diverse situations. Almost half of the total alarm-sets were _normal_task_ (48%), and the average number of days was the greatest among the wake-up tasks (54 days). Further, _normal_task_ tended to be used for alarms in the late morning hours (7.72--equivalent to 7:43 a.m.), which are likely less challenging. Finally, the consistency of using _normal_task_ tended to be lower than that of the other tasks in terms of both set and dismiss usage, possibly because of its frequent uses in diverse contexts. _picture_task_ is the hardest task and mainly used for challenging situations. Dismissing _picture_task_ tends to take a longer time (40 s), and the number of snooze uses was the greatest, \begin{table}
\begin{tabular}{l c c c c c c c} \hline \hline \multirow{2}{*}{**Variable**} & \multirow{2}{*}{_Beta_} & \multirow{2}{*}{S.E.} & \multirow{2}{*}{\(t\)} & \multirow{2}{*}{\(P>|t|\)} & \multicolumn{3}{c}{**95\% CI Exp (Beta)**} & \multirow{2}{*}{**VIF**} \\ \cline{4-4} \cline{6-9}  & & & & & **Lower** & & **Upper** \\ \hline (_constant_) & \(-0.164\) & \(0.007\) & \(-23.580\) & \(0.000\) & \(-0.178\) & \(-0.151\) & \(126.656\) \\ \(freq\_use\_days\) & \(0.004\) & \(0.000\) & \(15.302\) & \(0.000\) & \(0.000\) & \(0.000\) & \(1.371\) \\ \(prop\_use\_days\) & \(-0.040\) & \(0.004\) & \(-9.35\) & \(0.000\) & \(-0.049\) & \(-0.032\) & \(1.499\) \\ \(avg\_ring\_hour\) & \(0.005\) & \(0.000\) & \(16.422\) & \(0.000\) & \(0.004\) & \(0.005\) & \(1.464\) \\ \(sd\_ring\_hour\) & \(0.001\) & \(0.000\) & \(0.451\) & \(0.652\) & \(-0.001\) & \(0.001\) & \(1.541\) \\ \(prop\_weekday\) & \(-0.041\) & \(0.006\) & \(-6.722\) & \(0.000\) & \(-0.053\) & \(-0.029\) & \(1.170\) \\ \(sd\_daily\_alarm\) & \(0.065\) & \(0.001\) & \(45.927\) & \(0.000\) & \(-0.062\) & \(0.067\) & \(1.269\) \\ \(prop\_recur\) & \(0.017\) & \(0.002\) & \(8.886\) & \(0.000\) & \(0.013\) & \(0.021\) & \(1.158\) \\ \(avg\_task\_completion\_time\) & \(0.027\) & \(0.000\) & \(401.445\) & \(0.000\) & \(0.027\) & \(0.027\) & \(1.745\) \\ \(sd\_task\_completion\_time\) & \(-0.011\) & \(0.000\) & \(-76.479\) & \(0.000\) & \(-0.011\) & \(-0.010\) & \(1.757\) \\ \(avg\_freq\_snooze\) & \(0.098\) & \(0.002\) & \(42.768\) & \(0.000\) & \(0.094\) & \(0.103\) & \(1.041\) \\ \hline \multicolumn{9}{c}{\(F(10,211,262)=22,110,p<0.001;R^{2}=0.511\).} \\ \end{tabular}
\end{table} 
Table 4: Multiple linear regression for identifying hard-tasks. indicating that _picture_task_ is the most challenging task to be completed among the wake-up tasks. The higher level of the difficulty probably causes users to usually set _picture_task_ for challenging contexts. The average set-hour of _picture_task_ was the earliest (6.88 h), and its standard deviation was the lowest. Moreover, the overall frequency of the _picture_task_ use was the lowest. _picture_task_ is more valuable and useful when the user is desperate to awaken on time, especially in the earlier morning. _math_task_ is also a difficult type, but its psychological barrier seems lower than that of _picture_task_. Similar to _picture_task_, _math_task_ takes a longer time to complete (40 s). However, the frequency of the _math_task_ use was greater than that of the _picture_task_ use by almost five times. Further, its number of snooze uses was much lower than that of _picture_task_. Such differences between _math_task_ and _picture_task_ occur possibly because these tasks cause different types of task load. _picture_task_ causes a physical load, while _math_task_ a cognitive load.