Semistatic Animation-Integrating Past, Present and Future in Map Animations

摘要

Visualisation of spatio-temporal information has been a challenge for cartography for decades. The earliest approaches focused on static visualisations, several of them with great success (Monmonier, 1990; Friendly, 2002; Tufte, 2006). With the digital age, dynamic and animated maps have become possible. Much work has gone in to the design and study of perception of both of these map types (Harrower et al., 2000; Midtbo, 2001a; Midtbo et al., 2007; Fabrikant et al., 2008) Several very effective animated maps have been developed and rigorously evaluated. Both static and animated visualisations have their distinct qualities. Static maps are able to provide the user with unlimited viewing time of the information, allowing the level of detail to be high. On the other hand, static maps do not have the intuitiveness of visualizing temporal information due to their inherent static nature. Animated maps are often more intuitive in their representation of temporal information. Displaying frames of information in rapid succession is perceived as more intuitive representation of the temporal information. However, the fact that the frames have a very limited viewing time often hinders the user from perceiving and gaining knowledge from the information (Harrower, 2009). There has been a sharp distinction between animated and static maps in cartography. Evaluation of either two has been following this distinction and often compared animated against static maps. In this article, we propose moving beyond the sharp distinction of animated and static maps by combining the qualities of both in one new representation method. To emphasize the concept’s qualities from both static and animated maps, we call this concept, semistatic animations. The core idea of the concept is to make all information visually available to the user at any given time of the animation. This allows the user to look both back and forth in the animation, while it is playing without interaction. The design draws inspiration from both static multiple map displays and diagram maps-qualities from both of these are integrated in an animated representation. A proof-of-concept implementation has been made using weather map animations. In order to assess the perceptual performance of the concept, a web experiment has been conducted. Realizing that the maps do not necessarily support all usage scenarios, a task-oriented approach was applied on the experiment. In total, the experiment included 240 participants. Results from the experiment revealed that the semistatic concept significantly increases the performance on several of the tasks compared to the equivalent traditional animated map. However, for some of the tasks, the semistatic approach did not improve the performance, or worsened it. This illustrates the importance of evaluating not only on a general level but delve further in different user tasks. The results obtained additionally motivates for further investigation of the semistatic concept as well as user behaviour.