Thesis (Ph.D.)--University of Washington, 2022App designers often exploit psychological vulnerabilities to maximize clicks, views, and time on site. When people attempt to resist such media use, their failure rate is higher than for any other temptation in everyday life. Consequently, users often report feeling dissatisfied and regretful of the time that they spend in apps. In response, concerned design practitioners and researchers have innovated ‘screen time tools’ that let users track and limit the time they spend on digital devices. Yet users report that reducing screen time is a poor proxy for their actual goals, that they are concerned with not only the quantity but also the quality of the time they spend online, so the problem persists. In this dissertation, I investigate how to respect the user’s time and attention by designing digital interfaces for a greater sense of user agency, i.e., the experience of control over one’s actions and their outcomes. My research on the YouTube mobile app, a common site of problematic use, finds that a majority of user goals are about shifting the quality of the content they consume on smartphones, not the quantity. Through a survey and co-design activities, I identify specific features that lead users to feel more or less control over how they spend their time on YouTube. Based on these features, I design and develop the SwitchTube mobile app, in which users can toggle between two interfaces when watching YouTube videos: Focus Mode (search-first) and Explore Mode (recommendations-first). In a field deployment of the SwitchTube app with 46 U.S. participants, I find that Focus Mode helps them realize a greater sense of agency without reducing their time spent in the app. My work highlights the need to think beyond ‘screen time’ and advances sense of agency as an alternative lens for addressing user frustrations. I highlight how the design community might identify and call out ‘attention capture dark patterns,’ conceptualize and measure sense of agency, and how flexible interfaces might adapt support for sense of agency to suit different use cases. Ultimately, sense of agency is not only associated with positive technology use outcomes, but also matters to users in its own right as a basic psychological need
