Human centred design of software agent in social network service against privacy concerns

Abstract

The rapid growth and influence of social network services has led many scholars to focus on privacy issues. However, the research described in this thesis was motivated by the small number of design studies that have focused on practical approaches to identifying tacit information from users’ instant non-verbal responses to privacy issues. The research therefore aimed to propose persona models as a design solution for software agent development based on the analysis of users’ emotional and behavioural responses, so as to address privacy issues in social network services. In the definition phase, 21 stakeholders belonging to three key stakeholder groups were recruited for unstandardised semistructured email interviews. Three main considerations for the design of software agents in social network services emerged from the interviews, which were classified into the following categories: comprehensive understanding of users’ perceptions of privacy; user type recognition algorithm for software agent development; and existing software agent enhancement. In the development phase, 50 participants were recruited for the Facebook case study, which included three research strategies: perceptions of privacy questionnaire for user typology; emotional response measurement using Geneva Emotion Wheel; and behavioural response observation using a contextual inquiry method. The participants were classified into four user types by means of cluster analysis: uninformed, trustful, suspicious and neglectful. Each user type’s key emotional responses were identified using Kruskal-Wallis test and Mann-Whitney U test, and key behavioural responses using affinity diagrams. This generated persona models of each user type that reflected the correlations between users’ perceptions of privacy, key emotional responses and key behavioural responses. Two fundamental features of the software agent were also proposed based on the persona models: confirmation and guidance. In the validation phase, software agent prototypes were created based on the proposed persona models. A total of 206 participants completed the online survey which included two sections: perceptions of privacy questionnaire for user typology replication, and key emotional responses measurement before and after the intervention of the software agent prototypes. Cluster analysis replication validated the proposed user typology, and Wilcoxon signed-rank test of key emotional responses validated the proposed persona models. By implementing the research outcomes, the software agent described in this thesis would be able to provide users with appropriate services based on their user types, to reduce the number of those who are still unaware of privacy practice and those who neglect their accounts, and to expand the size of a user group pursuing sound relationships.