Validation and Extension of Zario, a Mobile Application to Counter Problematic Smartphone Use

This research project aimed to empirically validate the effectiveness of the "Zario" app, a mobile application that uses "micro-challenges" to prompt conscious and deliberate reduction of self-reported problematic smartphone use (PSU). Following up on recent calls for a complementation of self-report measures of PSU with direct, objective measures, I further tested whether the app would affect total screen time and pick-up frequency. In a pre-test post-test design, participants were randomly assigned to either the experimental group using the app (n=15) or an active control group (n=16) that did a one hour daily digital detox. Results showed no significant interaction between the two groups on PSU, yet post-hoc analysis showed significant reductions in PSU in both groups which can be explained by the active control group design. In both groups, a significant number of at-risk participants fell below the addiction cut-off after the intervention week, with the effect being more pronounced for those using the Zario app. Furthermore, I found a marginally significant interaction with regard to screen time, participants using the app had higher reductions in screen time than did participants in the active control group. Next to the empirical study, the project served as a post-hoc theoretical substantiation of the apps working mechanisms. Based on an extensive literature review, I analysed the app through the lens of dual-process theory and proposed a new feature, the "Circuit Breaker," which targets automatic and non-conscious processing. Next to providing an empirical validation of the effectiveness of the "Zario" app in reducing PSU, the project also provides a good example of a constructive feedback loop between empirical testing and practical implementation in the field of digital well-being that can serve both to refine existing tools and solutions, as well as to gather valid real-world data.