Vision is by far our most powerful sense. Seeing and thinking are intimately connected. To display data effectively, we must understand a bit about visual perception, gleaning from the available body of scientific research those findings that can be applied directly to dashboard design: what works, what doesn't, and why.
Understanding the limits of short-term memory
Visually encoding data for rapid perception
Gestalt principles of visual perception
It isn't accidental that when we begin to understand something we say, "I see." Not "I hear" or "I smell," but "I see." Vision dominates our sensory landscape. As a sensophile, I cherish the rich abundance of sounds, smells, tastes, and textures that inhabit our world, but none of these provides the rich volume, bandwidth, and nuance of information that I perceive through vision. Approximately 70% of the sense receptors in our bodies are dedicated to vision, and I suspect that there is a strong correlation between the extensive brainpower and dominance of visual perception that have co-evolved in our species. How we see is closely tied to how we think.
I've learned about visual perception from many sources, but one stands out above the others in its application to information design: the book Information Visualization: Perception for Design by Colin Ware. Dr. Ware expresses the importance of studying visual perception beautifully:
Why should we be interested in visualization? Because the human visual system is a pattern seeker of enormous power and subtlety. The eye and the visual cortex of the brain form a massively parallel processor that provides the highest-bandwidth channel into human cognitive centers. At higher levels of processing, perception and cognition are closely interrelated…However, the visual system has its own rules. We can easily see patterns presented in certain ways, but if they are presented in other ways, they become invisible…The more general point is that when data is presented in certain ways, the patterns can be readily perceived. If we can understand how perception works, our knowledge can be translated into rules for displaying information. Following perception-based rules, we can present our data in such a way that the important and informative patterns stand out. If we disobey the rules, our data will be incomprehensible or misleading.
Note: Colin Ware, Information Visualization: Perception for Design, Second Edition (San Francisco: Morgan Kauffman, 2004), xxi.
We'll concentrate our look at visual perception on the following areas:
Each of these topics can be applied directly to the design of dashboards.