Combining linking & focusing techniques for a multiple hierarchy visualisation

Visualisations have previously combined linking and brushing operations successfully. However, none to our knowledge have combined linking and focussing techniques. We describe the motivation behind developing such a technique, and show how our visualisation takes advantage of inherent links in a set of multiple overlapping hierarchies to build a mechanism that can produce linked focus + context effects between these multiple hierarchies with a single user action. Previously, our visualisation had utilised linking only, using colour to highlight correlations between distinct but overlapping hierarchies.