The use of color is valuable but care must be taken. There have been published many heuristics about the proper use of color for display and information communication, but these may not apply to the investigation.
For example, studies have shown that variations in hue are good for displaying nominative data (such as different types of objects) but not for ordinal, interval, or ratio data. Different hues do not imply magnitude differences, e.g., it is not obvious that a green object has a higher value than a blue object.
Different brightness levels (Value in an HSV model) or saturation levels of a given hue do convey differing magnitudes. A gradual change from one hue to another can also be used for this.
Another problem is that some users may be color blind. In general, individuals do not perceive colors exactly alike, and color perception changes with age.
One method to better show the 3D nature of an object is to use lighting and shading models. But if this is used in conjunction with a color scale to show value then the result can be confusing.
Last modified on March 29, 1999, G.
Scott Owen, firstname.lastname@example.org
HyperVis Table of Contents