## 3 Methodology
### Alarmy Usage Data
#### 3.1.2 Dataset Overview  
Table 1 shows the description of alarm usage variables and the statistics that we measured for each individual user. We collected Alarmy usage data from the real users who voluntarily downloaded and installed the app in the US from January to May 2018 (151 days). The collected usage log includes anonymized user ID, the time when the alarm was set, the time when the alarm was set, the details of the alarm-set (e.g., wake-up task type, set to recur), the time when the alarm was dismissed, and the number of snooze uses. The consent required for data collection from these users was exempt by the approval from the Hanyang Institutional Review Board (IRB No.: HYU-2019-06-010-1).  
During the study period, a total of 581,712 users left 48,763,070 usage logs. To exclude trial users, we selected 211,273 Alarmy users who had used the app for more than 30 days and their 42,909,263  
\begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Category** & **Variable** & **Description** & **Mean** & **SD** \\ \hline
**Set Frequency** & _freq\_use\_days_ & The number of days using the alarm & 73.67 & 30.47 \\  & _prop\_use\_days_ & Proportion of the days using the alarm & 0.66 & 0.18 \\  & _avg\_daily\_alarm_ & Average number of alarms in a day & 1.68 & 0.69 \\ \hline
**Set Time** & _avg\_ring\_hour_ & Average of ringing hours & 7.43 & 2.72 \\  & _prop\_weekday_ & Proportion of alarms set for weekdays & 0.84 & 0.11 \\ \hline
**Set Consistency** & _sd\_daily\_alarm_ & SD of the number of alarms in a day & 0.676 & 0.50 \\  & _sd\_ring\_hour_ & SD of ringing hours & 2.14 & 1.68 \\  & _prop\_recur_ & \% of the alarms set to recur weekly & 0.77 & 0.35 \\ \hline
**Dismiss Time** & _avg\_task\_completion\_time_ & Average time to dismiss the alarm after & 19.59 & 12.21 \\  & _sd\_task\_completion\_time_ & \begin{tabular}{l} it went off (seconds) \\ \end{tabular} & \
\begin{tabular}{l} 13.86 \\ \end{tabular} & 5.88 \\  & _sd\_task\_completion\_time_ &
\begin{tabular}{l} SM of the seconds to dismiss the alarm \\ after it went off (seconds) \\ \end{tabular} & 0.18 & 0.28 \\ \hline
**Snooze** & _avg\_freq\_snooze_ & Average number of delays to dismiss an alarm & 0.30 & 0.27 \\  & _sd\_freq\_snooze_ &
\begin{tabular}{l} SM of delays to dismiss an alarm \\ \end{tabular} & 0.30 & 0.27 \\ \hline \hline \end{tabular}
\end{table}
Table 1: Alarm usage variables.  
app usage logs. They were 38% of the total users, but their usage logs cover 88% of the entire dataset. From the usage logs, we measured alarm usage behaviors in two folds: alarm-set and alarm-dismiss. The alarm-set usage contains eight variables in three subcategories: (1) set frequency, (2) set time, and (3) set consistency. Alarm-dismiss usage includes four variables from the two subcategories, (1) dismiss time and (2) snooze.  
The average number of the days that the users set the alarm was 74 days, and the users usually set 1.68 alarms per day. The alarms mostly occurred in the early morning hours (7.43 h) on weekdays (84%). Further, most of the alarms were set to recur (77%). The most common task was _normal_tasks_ (71%), followed by _math_tasks_ (15%), _shake_tasks_ (10%), and _picture_tasks_ (4%). On average, it took about 19 s to dismiss an alarm (Normal: 14.1 s; Picture: 40.06 s; Shake: 26.62 s; Math: 40.81 s).