Since the mechanisms of human perception have an enormous impact on the effectiveness of visual representation, an awareness of the characteristics of perception should provide the foundation for visualization design. Careful attention to the mechanisms and characteristics of human perception can yield more effective visualizations by exploiting the strengths of the visual system and avoiding its weaknesses. Additionally, visualization design should ensure that the most striking aspects of a visualization are also the most important. Representations which draw the viewer's eye to unimportant features may cause more interesting features to be overlooked. Consideration of the characteristics of human perception can be a valuable guide in predicting which aspects of a visualization will draw the attention of the average viewer. Feature attributes that influence attention include color, size, opacity/density, order, motion, and style.

Perceptual inspiration for effective visualization techniques need not come directly from the workings of the visual (and other sensory) system. Practitioners of a variety of fields of visual communication, such as technical illustration, graphic design, and art, have been developing techniques which exploit human perception and cognition for hundreds of years. These fields provide fertile sources of examples, techniques, heuristics, and tricks that represent the application of understanding of perceptual capabilities to visual communication. This understanding of perceptual capabilities may be explicit, flowing from direct study of the perceptual mechanisms, or implicit, based in intuition or the study of visual media.

Issues I would like to discuss include:

• How can we increase the accessibility of knowledge and experience in other fields to visualization researchers and practitioners?
• How can we apply knowledge about perception more directly and productively to visualization challenges?
• How can we get the spectrum color scale replaced as the defacto standard?