Figure 1
From: Social network differences of chronotypes identified from mobile phone data
Identifying individuals’ chronotypes. The chronotypes of participants are determined by computing the average hourly frequencies of the “screen-on” events of their mobile phones for the first four weekdays. Each participant’s pattern is compared to the population average (solid gray line). For chronotype identification, the gray and yellow time ranges are used. If a participant has above-average levels of activity (plus sign) in the night-time gray time range and below-average levels of activity (minus sign) in the yellow morning time range, she is categorized as an evening-active owl (panel (A)). Participants of the opposite pattern (below-average night-time activity and above-average morning activity) are categorized as morning-active larks (panel (B) depicts the pattern for a morning-active person). For details, see Materials and Methods