Visualizations facilitate presenting information in a form adapted to human visual system. The thesis defines this adapting more precisely with a framework of human-visualization interaction. Human capacity limits are used to identify critical subtasks in interaction that specify whether the data quantities and complexity of relations are understandable. In reality, use context and personal characteristics also impact understanding. The framework identifies commonalities of human processing in context of large quantities of multi-dimensional data. The novel extension is to identify multi-dimensionality from tasks of ordinary people, such as shopping or voting. According to the hypothesis ordinary people can also understand more complex information with the help of visualized dimension-reduction algorithms (e.g., MDS or SOM). Such context and haste give prominence to perceptual and cognitive processes, the critical subtasks, and the related visual parameters. Unfortunately, the interactive effects of the related parameters on performance cannot be predicted with real applications, and thus applied studies are needed. The proposed multi-disciplinary framework is based on reviewing empirical findings about humans. First, cognitive science about human concept formation is used to provide indications about how to pre-processes data into more readily understandable form. Second, vision research, experimental psychology, and neuroscience are used to explain the interaction, when information is received through vision and the input is influenced through gaze shifts and manual operations. Third, findings are reviewed about conditions, in which processing is likely to be externalized to visualization or tool as opposed to being performed by human mind. The framework is then applied for psychophysically controlled reaction time and eye movement experiments based on selective review of methods and critical visual parameters in research of visual searching. The evaluated tasks, searching and integrating, were chosen based on both behavioral studies with visualizations and implications of the framework. The ordinary people interacting with visualizations were evaluated indirectly from the popularity, feedback, and observations during two Finnish elections. The framework led to three suggested principles. First, externalizing memory tasks and information processing to visualizations reduces mental load. Second, relations of dimensions can be uncovered by perceiving consequences of own manual actions. Third, peripheral vision is suitable for representing coarse outlines, for instance depicting dimension reduction. Facilitating rapid gaze shifts is important for all of these principles.
|Translated title of the contribution||Ihmisen kyky havaita, ymmärtää ja hallita moniulotteista informaatiota visualisointien avulla|
|Publication status||Published - 2012|
|MoE publication type||G5 Doctoral dissertation (article)|
- eye movements