Table 1.
Feature type | Name | Description |
---|---|---|
GPS | Location variance | The logarithm of the sum of the statistical variances in the latitude and the longitude of all GPS coordinates in the day |
Location entropy | The variability of the time that participants spend in significant places in the day | |
Normalised location entropy | The location entropy divided by the logarithm of the number of significant places | |
Time at home | Home is defined as the most frequent significant place where a participant spent the most time between 0 to 6 am; time at home is defined as the percentage of time a participant spent at home relative to other significant places | |
Total distance | The total distance covered by a participant during the day | |
Communication | Total calling frequency | The number of times that a participant answers and makes phone calls during a day |
Total calling duration | The total time in minutes that a participant spends each day answering and making phone calls (in min) | |
Non-working time calling frequency | The number of times that a participant answers and makes phone calls at times other than 8 to 6 pm during a day | |
Non-working time calling duration | The total time that a participant answers and makes phone calls at times other than 8 to 6 pm during the day (in min) | |
Number of missed calls | The number of calls that are marked as missed during the day | |
Number of contacts | The number of contacts a participant answers and makes phone calls during the day | |
Calling entropy | The variability of calling durations a participant spends in contacts during the day | |
Normalised calling entropy | Calling entropy divided by the logarithm of the number of contacts during the day | |
Phone usage | Phone usage frequency | The number of times that a participant interacts with their phone during a day |
Phone usage duration | The total time in minutes that participants spend each day interacting with their mobile phones | |
User activity | Lock screen duration | The total time in minutes that participants lock their mobile phones during the day |
Number of used apps | The number of applications that a participant uses during the day | |
Midnight app usage | The number of applications that a participant uses between 0 to 5 am during the day | |
Sleep time | Sleep time [min] is considered to be between the last time an app was used in the previous day (or in the same day before 2 am if available) and the first time an app was used after 5 am |
Four types of features have been derived: GPS, communication, phone usage as well as user activity features.