Exploring the Effectiveness of Social Media Appeals in the Search for Missing Persons

Student thesis: Doctoral Thesis


The overarching aim of this PhD thesis was to explore the impact and effectiveness of social media-based publicity appeals for missing persons through the exploration of social media bias, the role of platforms and technologies and user motivations to engage and share missing persons appeals. This thesis applies innovative methodologies such as manual and automatic web scraping techniques and provides a thorough methodological discussion regarding such approaches of collecting non-obtrusive data and digital methodologies. Ethical issues are discussed in consideration for data collection techniques. Study 1 aimed to build a demographic profile of missing individuals who receive publicity appeals on social media and to assess platform differences between Facebook and Twitter in relation engagement levels. The results highlight key platform differences and how the public engages with appeals on Facebook and Twitter. Study 2 aimed to further explore appeals posted on Twitter using a longitudinal approach to assess changes in network structures of Twitter accounts engaging with the Missing People Charity and explore the impact of missing persons characteristics on engagement levels. Results highlight key practical implications of managing appeals on Twitter to promote privacy and further safeguarding of the missing individuals. Study 3 explored user motivations through the understanding of social media-based affordances and propensity to engage in social action in the context of missing persons appeals online and offline. The results highlight the importance of user motivations and are discussed in terms of practical implications of promoting empirically based social media strategies in appealing to the public to aid in the search for missing persons. These studies have contributed to a clear gap in research focusing on the role of digital social media technologies in aiding missing persons investigations. This thesis is also the first to apply social network analysis techniques in assessing the impact of social media-based publicity appeals. Theoretical implications for understanding social media users and organisational use of social media are discussed throughout the individual studies. Future research and practical implications and recommendations are discussed to promote strategies which focus on safeguarding missing individuals in a digital context.
Date of Award16 Sept 2023
Original languageEnglish
Awarding Institution
  • University of Portsmouth
SupervisorKaren Shalev (Supervisor), Craig Collie (Supervisor) & Carl Jeffrey Adams (Supervisor)

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