- Consistent designs use orderly layouts that align labels and group related items. They include appropriate color-coding to show relationships among components, provide warnings where needed, and highlight special cases. Consistent designs stick with meaningful terminology and present understandable sequences of InstructIons. Consistency is often invisible, because keeping the corporate logo in the upper left-hand corner or using the same color scheme seems natural. Only when the logo jumps to the right or the colors change do you notice.
- Predictable designs enable you to gain familiarity and confidence in using your computers because you have a clear model of what will happen after each selection. You expect, after putting a book in an electronic shopping cart, that you can remove it or return to it a week later. Predictable designs apply meaningful metaphors, such as a shopping basket or e-mail in-box, and familiar conventions, such as the use of Save, Print, Open, and Close.
- Controllable interfaces give you the power to do what you want. You can combine a photo with text to make a wedding invitation or copy part of a spreadsheet into an e-mail document. When you change your mind, you can revert to a previous version of your invitation or reformat the spreadsheet to provide input for a simulation program. Controllable interfaces are adaptable by users so that they can customize their screens and avoid unneeded features.”
From: Shneiderman, B. (2002), Leonardo’s Laptop: Human Needs and the New Computing Technologies, Cambridge, MA: MIT Press, p. 64-5