Critique strength: popout for extreme attributes [Johnson and Shneiderman. Treemaps: A Space-Filling Approach to the Visualization of Hierarchical Information Structures. Proc. IEEE Visualization 1991.] [www.smartmoney.com/marketmap] weaknesses: difficulties seeing structure [van Wijk and van de Wetering. Cushion Treemaps. Proc. InfoVis 1999] 27