11 CONSTANT COMPANION: A WEEK IN THE LIFE OF A YOUNG PERSON'S SMARTPHONE USE © COMMON SENSE MEDIA. ALL RIGHTS RESERVED.
Study design
A diverse sample of 203 U.S. preadolescents (ages 11 to 12)
and adolescents (ages 13 to 17) with their own smartphones
were recruited by Horowitz Research between August and
November 2022 (see Table 1). Parents and caregivers of
tweens and teens were contacted with brief information
about the study, and if interested, provided informed consent
for the child and shared the child's email address. Children
were then contacted by email and provided online informed
consent before completing a baseline questionnaire and
installing the Chronicle app (Methodic, Inc) onto their smart-
phone. Eligibility criteria included: 1) ages 11 through 17; 2)
speaks English or Spanish fluently enough to complete
informed consent and surveys; 3) has their own Android
(version 6.0 or above) smartphone (e.g., Samsung, Google
Pixel, Motorola, etc). iPhone users were not included because
data collection access for detailed app usage (i.e., names of
specific apps such as YouTube, Snapchat, etc.) was not avail-
able for researchers at the time of data collection. The study
was approved by the University of Michigan IRB.
Baseline surveys
Parents reported their educational attainment, household
income, and their child's race/ethnicity. Child participants
completed a brief online survey that included the Technology
Impairment Scale (six items, alpha = 0.76, Burnell & Odgers,
2023, adapted from Meerkerk et al., 2009) which assesses
compulsive technology use or interference with daily activi-
ties (e.g., Do you feel restless, frustrated, or irritated when you
cannot access the internet or check your mobile phone? Do you use
technology to escape from your sorrow or get relief from negative
feelings?) on a response scale of 0 = never, 1 = sometimes, 2 =
often.
Mobile device tracking
Participants were instructed on how to install and set up the
Chronicle app and keep it running on their device for nine
complete days. This app was developed with NIH funding,
pilot-tested and validated against pen-and-paper logs of
smartphone use, and has been used in child and parent popu-
lations (Radesky et al., 2020). After nine days, participants
were contacted and prompted to uninstall Chronicle and data
were exported from the Methodic Chronicle dashboard.
Chronicle provides timestamped data about which app is
running in the foreground and when pickups and notifications
occur, but does not collect information about contacts,
message content, which websites are visited, or what content
is viewed on platforms. In the informed consent form, partici-
pants were provided clear explanations of what data would be
collected, how it would be used, and how soon it would be
deleted.
Data cleaning and inspection processes were used to identify
any missing gaps in smartphone data (e.g., no data for >12
hours) and reduce the duration of apps that sometimes run
long but are not true usage (e.g., launcher, screen saver, alarm
clock). Some participants' data crossed two time zones, indi-
cating that they traveled during data collection, so we
removed the time zones that occurred on fewer days before
analyzing time-stamped data. We visually inspected all over-
night data to ensure that it showed data characteristics of true
usage (i.e., rather than data irregularities that occasionally
occur). Chronicle data was then processed to calculate hourly
and daily duration, pickups, and notifications, as well as dura-
tion and notifications for popular apps and app categories.
Notification and pickup data were not available for four par-
ticipants with older versions of the Android operating system.
Data for each participant were also visualized using R.
App categorization
We pulled data from the Google Play store API corresponding
to each app package name, including the app category (e.g.,
gaming, photography, shopping, social) and content rating
(e.g., Everyone, Teen, 17+, 18+/Adult). Apps that could not be
found on the Play store were manually categorized. We col-
lapsed or expanded some categories to reflect the main types
of apps used by 11- to 17-year-olds. For example, "communica-
tion" apps were recategorized into more precise categories
that reflect different uses, such as calls, email, or chat/messag-
ing. We categorized any app as Social Media if it involved a
non-SMS platform that facilitated the exchange of text, video,
and photo content with interaction by users (e.g., Snapchat).
However, we separated YouTube into its own category (includ-
ing YouTube, YouTube Kids, and YouTube TV) because of the
unique usage patterns YouTube has shown in our prior work
(e.g., Radesky et al., 2020).
Methodology