This essay examines social nudging and influencing factors on user choices on the two mobile apps Foodora and Uber Eats that offer services for food delivery, and whether there are any connections between these factors and the interface design. This type of service has in recent years become popular with the digitization of society. To investigate this, the survey was designed and analyzed based on factors from Fogg's behavior model, as well as categories for interface design from previous research. This study was based on a qualitative research strategy with a focus on deeper descriptions from six selected participants. Data were collected through a test on an interactive prototype combined with a semi-structured interview to achieve the purpose of this study about how digital social nudging affects user choices. The study showed mixed results. The social nudging feature in the form of ratings turned out to have a great influence on user choices, while the feature in the form of popular choices did not. This indicates that some methods of social nudging may be more favorable than others in this type of environment. A new factor was also identified, preference, which turned out to influence user choices more than the social nudging in the form of popular choices. The results also showed a connection between the influence of nudging and the interface design of the apps, as the design may have been influential for whether the social nudging benefits users or not.

Recognizing the importance of food waste as an environmental and social problem, this thesis aims to test nudging as a successful tool to promote a pro-environmental behaviour towards food waste reduction. The present research uses an experiment in a university canteen in Gotland, Sweden, with two interventions - posters with informational prompts and practical tips. Through quantitative analysis, we were able to conclude that nudging reduced overall food waste but with no statistical significance for the informational treatment. Furthermore, the informational prompts and the suggestions of shortcut solutions had similar positive impacts on food waste, with no significant difference. However, the study highlights some aspects that limit these results to a short-term perspective due to the experimental period of two months. On the other hand, the complementary qualitative data from interviews with customers revealed that nudges, especially practical suggestions, can be more useful as an awareness tool rather than a technique to actually change behaviours. Overall, the findings show that the two interventions reduced food waste with a continuous decreasing trend. Therefore, nudging can be a useful technique for canteens and restaurants to influence consumers’ behaviour towards food waste reduction.

This thesis acknowledges the increasingly important issue of global freshwater scarcity. It focuses on water consumption in private households and examines whether social nudging, specifically the focus theory of normative conduct, can serve as a tool to reduce it. This is examined through action research conducted on the island of Gotland, Sweden, in cooperation with the local major housing company GotlandsHem. Despite some limitations, the findings show with a significance of 0.033 that, on average, almost 50 litres of water less were used weekly by each household after two social nudging interventions. This corresponds to 7,472.99 litres for all 151 nudged households. The findings show that the research design represents a way for housing companies to use the focus theory of normative conduct from the field of social nudging to reduce their tenants’ water consumption.