Tese de doutoramento, Informática (Engenharia Informática), Universidade de Lisboa, Faculdade de Ciências, 2017With the increasing popularity of location based services and mobile tracking technologies, the collection of large amounts of spatio-temporal data became an increasingly common, easier, and more reliable task. In turn, this has emphasized the possibility of analysing georeferenced information, particularly associated with human trajectory data, to identify and understand movement patterns and activities, ultimately, supporting decision making in various contexts. In order to properly analyse and understand the spatio-temporal and the thematic properties associated with these data, adequate visualization techniques are needed. Due to the spatial properties of trajectories, map-based techniques, such as 2D static maps or 3D space-time cubes (STCs) are considered as essential tools for their visualization. However, despite the increasing number of visualization systems, the study regarding their usability, alongside the role of the human user, sometimes with a limited background in data visualization and analysis, are often neglected. In addition to the somewhat disperse, and sometimes even contradictory, results in the literature, these factors, ultimately, emphasize the lack of knowledge to support the choice of particular visualizations, and their design, in different types of tasks. This dissertation addresses these issues through three main sets of contributions, focusing on inexperienced users, in terms of data visualization and analysis: i) the characterization of the dis/advantages of existing map-based techniques (2D static maps and STCs), depending on the types of visual analysis tasks and the focus of the analysis; ii) the improvement of existing visualization techniques, either through the inclusion of additional spatial cues within the STC, or combining both types of techniques in various ways; and iii) the identification of design guidelines for trajectory data visualization, describing various considerations/criteria for the selection of different map-based visualization techniques and their possible interactive features
