The students encountered a lot of resistance to this idea. Now the application is catching on among realtors. Zooming and filtering have also been found useful for dynamic exploration of data to investigate trends and identify outliers. Showing multiple levels of view at once may help maintain context. Using color and thickness to indicate characteristics also seems promising.
Dense screens are powerful, but difficult to design.
Ethnographic methods and anomaly classification seem to have potential. Templates can help generate consistent interfaces. In every case the use of color enhanced selection. Colors are most useful when mapped to semantic factors like setting green for forests, blue for oceans. Colors may be used to induce grouping of non-contiguous items.