Human-centred design for sustainable behaviour change: Research, design and evaluation of a mobile application

Abstract

In this master's thesis on design for sustainable behaviour change, two research goals are addressed. Firstly, it is investigated how to design a mobile app that encourages people to take on sustainable actions across different areas of life (e.g. nutrition, mobility, waste). Secondly, it is investigated, to what extent such an app can support people in taking on more sustainable actions. The theoretical basis is the Theory of Planned Behaviour which is used as a general framework to understand and evaluate behaviour change. The app is designed in a human-centred approach addressing the user needs of the target group of young, sustainability-minded people. The designed app assigns high control to the user and supports through the design strategies of eco-information, eco-choice, eco-feedback, eco-spur and community elements. At the core of the app are sustainability challenges in which users participate, collaborate and compete in a community environment and receive targeted, personalised feedback and tips.

In a two-weeks field study, the app is tested with 30 target users. The analysis shows that, during the usage phase of the app, participants acted statistically significantly more sustainably with regards to the self-reported behaviours "nutrition", "tap water consumption" and "shower time" as compared to the pre-study measurement. Users' positive attitudes towards acting sustainably and their perceived behavioural control also statistically significantly increased. In particular, their awareness of potential sustainable activities to take and their knowledge about their impact on the environment increased.

Limitations of the study include the usage of non-validated questionnaires and self-reports, a small and highly homogenous test group and technological immaturities of the app that might have impacted the user experience. In the future, field studies should be expanded to more areas of life (e.g. travel, finances) and should be applied to a larger user group and over a longer period of time to investigate long-term effects of the usage of a sustainability app on behaviour change.