The Inspector: A Cognitive Artefact for Visual Mapping

Existing custom visualization tools provide cognitive artefacts that can reduce the cognitive barriers designers encounter in visual mapping, mapping data to visual primitives (e.g. ellipse, rectangle) and their properties (e.g. colour, size.) However, our experience with designers shows that the existing artefacts are insufficient. In particular, designers struggle to understand the relationship between visual primitives, their properties, and data. Moreover, it is hard to verify the correctness of the visual mappings. In response, we developed a new cognitive artefact, the inspector, that explicitly shows the data behind visual primitive and their properties. We evaluated the impact of the inspector on usability with seven designers. The result shows that the inspector reduced usability problems and helped designers verify the visual mappings.