We propose a rudimentary taxonomy of interactive data visualization based on a triad of data analytic tasks: finding Gestalt, posing queries, and making comparisons. These tasks are supported by three classes of interactive view manipulations: focusing, linking, and arranging views. This discussion extends earlier work on the principles of focusing and linking and sets them on a firmer base.
Next, we give a high-level introduction to a particular system for multivariate data visualization: XGobi. This introduction is not comprehensive but emphasizes XGobi tools that are examples of focusing, linking, and arranging views, namely: high-dimensional projections, linked scatterplot brushing, and matrices of conditional plots.
Finally, in a series of case studies in data visualization, we show the powers and limitations of particular focusing, linking and arranging tools. The discussion is dominated by high-dimensional projections which form an extremely well-developed part of XGobi. Of particular interest are the illustration of asymptotic normality of high-dimensional projections (a theorem of Diaconis and Freedman), the use of high-dimensional cubes for visualizing factorial experiments, and a method for interactively generating matrices of conditional plots with high-dimensional projections.
Although there is a unifying theme to this article, each section --- in particular the case studies --- can be read separately.
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Last modified: 10 June 1997
