By Gert-Jan Boos
In general there is a lack of knowledge on the usability of new visualisation techniques. This is a missed opportunity for the visualization field because in practise the new techniques are not used (optimal). This research was primarily aimed to research the usability of 3D visualization for multivariate thematic mapping. This is done by making a comparison between the well-known choropleth and the value-by-alpha, cartogram, 3D cartogram techniques. Based on literature research a questionnaire was developed that was completed by 38 participants. The focus of this research was on the effectiveness (by measuring the percentage of correct answers and the time used to answer the questions) per visualization, in different situations (univariate, multivariate). The results give a clear picture of the usability of the different visualisation techniques in relation to each other. The results show that the choropleth is most effective for univariate thematic mapping. And that the effectiveness of the 3d cartogram was not significantly different for multivariate visualization. This shows the potential of the 3D cartogram, considering that the participants were more experienced in reading choropleth maps. The results are useful for mapmakers and researchers who are interested in multivariate thematic visualisations.
Keywords: Thematic mapping, Visualization, 3D Cartogram, Usability, Choropleth, Cartogram