Unpacking expectancy in digital interventions for mental well-being

Although there are many digital interventions specifically designed for Mental Well-Being (MWB) support, low engagement and high dropout rates are commonly reported (Borghouts et al. 2021; Baumel et al. 2019). As people often bypass specialized tools in favour of general-purpose technologies for MWB, this thesis draws on expectancy as a lens to understand what impedes their uptake and use in practice, and to inform new design interventions. Across three empirical studies and an exploration of a design prototype, the thesis explores how expectancy shapes whether, in MWB contexts, digital technologies feel approachable or burdensome, relevant or misaligned and therefore frustrating. This thesis uncovers that expectancy narrows or broadens with MWB states and mediates how users interpret digital technology through effort and performance expectancy. Rather than creating new specialised applications from scratch, through the design prototype Chatty, the thesis also demonstrates how scaffolding by adding a lightweight mediating layer, can help better align general-purpose technologies with users’ needs and expectancies. By foregrounding expectancy as a mediating mechanism and a design principle, the thesis contributes both theoretical and practical insights and offers some crucial design implications.