Two of the greatest challenges in dashboard design are to make the most important data stand out from the rest, and to arrange what is often a great deal of disparate information in a way that makes sense, gives it meaning, and supports its efficient perception. An understanding of the preattentive attributes of visual perception and the Gestalt principles provides a useful conceptual foundation for facing these challenges. It is much more helpful to understand how and why something works than to simply understand that something works. If you understand the how and why, when you're faced with new challenges you'll be able to determine whether or not the principles apply and how to adapt them to the new circumstances. If you've simply been told that something works in a specific situation, you'll be stuck when faced with conditions that are even slightly different.
As you proceed into the coming chapters, you'll have several opportunities to reinforce your grasp of visual perception by applying what you've learned to several real-world dashboard design problems.