A Billiard Metaphor for Exploring Complex Graphs

Exploring and revealing relations between the elements is a frequent task in exploratory analysis and search. Examples include that of correlations of attributes in complex data sets, or faceted search. Common visual representations for such relations are directed graphs or correlation matrices. These types of visual encodings are often if not always fully constructed before being shown to the user. This can be thought of as a top-down approach, where users are presented with a full picture for them to interpret and understand. Such a way of presenting data could lead to a visual overload, specially when it results in complex graphs with high degrees of nodes and edges. We propose a bottom-up alternative called Billiard where few elements are presented at rst and from which a user can interactively construct the rest based on what s/he nds of interest. The concept is based on a billiard metaphor where a cue ball (node) has an e ect on other elements (associated nodes) when stroke against them.