Purpose: The purpose of this article is to evaluate effects of self-determination theory-based on-campus
and off-campus prevention programs on smartphone overdependence among university students.
Methods: This was a pre-posttest quasi-experimental study with a nonequivalent control group (CG).
Seventy-eight students were recruited as participants. They were allowed to choose either an experiment
group (EG) or a CG. On-campus smartphone overdependence prevention program was provided to
participants in experimental group 1 (EG1), while on-campus program combined with off-campus
prevention camp was provided to those in experimental group 2 (EG2). Instruments used in this
study included a smartphone overdependence self-diagnosis scale, a basic psychological needs scale, and
a self-regulation ability scale. Data collection was performed at baseline, immediately after intervention,
at 1 month and 3 months after intervention. Data were analyzed using mixed analysis of covariance.
Focus group interview was performed for qualitative evaluation.
Results: After the intervention, smartphone overdependence and basic psychological needs exhibited
significant interactions between group and time. Smartphone overdependence scores decreased in EG1
and EG2 but increased in CG (F ¼ 4.56, p ¼ .001). Basic psychological needs improved in EG1 and EG2 but
deteriorated in CG (F ¼ 5.04, p ¼ .009). Focus group interviews revealed that participants strived to
control their smartphone usage through individual efforts and by interacting with new friends in college
even after completing the program.
Conclusion: In this study, on-campus only program and combined intervention of on- and off-campus
programs were both effective in maintaining and managing smartphone use. However, participants
perceived that the off-campus program provided an opportunity to apply the theory learned in oncampus
to the real world.