Is It There Yet? Designing a User Interface For Messenger Apps That Use Disruption-Tolerant Networking in Crises

During crises, reliable communication is essential for seeking help. Peer-to-peer messengers using disruption-tolerant networking (DTN) can improve crisis communication by enabling data transmission even during Internet outages. However, understanding DTN is complex due to its unintuitive behavior compared to server-based messaging. While DTN research has primarily focused on technical aspects, our work investigates users’ mental models and comprehension of DTN. We use a baseline messenger app prototype, adjust its user interface (UI) by introducing new UI elements that visualize relevant metadata, and evaluate the UI in a mixed-design lab study, where participants ( N = 42) engage in chats with partners at varying proximities. Through a mixed-methods approach, including a novel evaluation methodology for understanding users’ mental models of DTN, we find that the redesigned UI improves users’ comprehension of network topology and reduces uncertainty about message delivery. Although the UI does not increase users’ tolerance of DTN latency, our study offers key insights into designing more transparent and supportive DTN-based messengers. Based on these results, we present an updated UI and highlight the implications for crisis communication.