Interacting with VDL-based structured icons on crisis map for emergency coordination: Interactive design and experimental demonstration

•VDL-based structured icon is no longer a kind of supplementary representation tool of emergency but a visual coordination center for all types of collaborators.•The correlation among emergency information could be represented through the visual similarity of the pre-icon of VDL-based icons.•Proposed interaction mode based on structured icon could reinforce the user’s cognition of dynamic information and optimize the whole emergency cooperation process. Accurate and timely information sharing among multiple participants is one of the crucial factors for collaboration in crisis management. The icon-based map was frequently applied as an effective means for crisis interaction and collaboration. However, former studies only regarded the icons as supplementary visualization components during the whole crisis collaboration process. In this paper, the concept of a structured-icon-relied interactive method was proposed to directly integrate all kinds of crisis and coordination information through icons on the crisis map. Moreover, structured icons are supposed to explicitly show the correlation among crisis information and to improve the interactive experience of information search. The effectiveness of this interactive method was verified by a controlled experiment with three sub-tasks for simulated crisis rescue. The results of the experiment showed that the design of the crisis map based on structured icons had a positive impact on collaborative decision-making and crisis interaction. The dynamic characteristics of the structured icon could represent the temporal and spatial attributes of crisis information and enhance users’ crisis coordination ability. The study aims to enrich the theory of crisis information visualization and interaction based on structured iconic representation. In practice, this research could optimize the design of a crisis collaboration system based on the icon as well as the interaction between people, crisis information, and collaborative system, which in turn provides accurate and timely rescue decisions.