Wednesday, November 16, 2011

Reaction: Tree-Maps: A space filling approach to visualization of hierarchical information structures

In this paper the author proposes a interactive visualization method tree-Map for the visualization of hierarchical structures. The main objectives of Tree-Map being efficient space utilization, interactivity, compression and aesthetics. The author explains the method with the help of a OS directory tree structure. This is an excellent example since it relates closely to daily use. The author goes step by step from simple listing to tree representation, Venn diagrams to finally reach at the tree-map representation. The paper further explains the general Tree-Map representation and supporting algorithms.
The Tree-Map representation can highlight some important characteristics of a tree structure like hierarchy, relative weights, the grouping of similar objects using different techniques like color, hue, borders etc. However, the claim of the author of efficient space utilization and aesthetics seems to be suspicious. Specially, the figure representing Tree-Map of 1000 files seems to be too cluttered to derive any interesting information from it. Also, the author fails to stress the objective of interactivity by tracking of cursor movement. Possibly a working Tree-Map visualization may clarify some of the points.