From hierarchies to polyarchies: visualizing multiple relationships

Hierarchy visualization has been a hot topic in the Information Visualization community for the last decade. A number of hierarchy visualization techniques have been invented, with each having advantages for some applications, but limitations or disadvantages for other applications. No technique has succeeded for a wide variety of applications. We continue to struggle with basic problems of high cognitive overhead (e.g., loss of context), poor fit to the data (e.g., problems of scale), and poor fit to the user's task at hand (e.g., handling multiple points of focus). At the same time, information access improvements have made available to us much richer sources of information, including multiple hierarchies and other relationships. I call this broader problem Polyarchy Visualization. In this talk, I will review what we know about hierarchy visualization, illustrate the broader polyarchy visualization problem with some examples, and introduce some novel polyarchy visualization techniques.