A picture may be worth a thousand words, but a user interface needs real words to clearly indicate what the user needs to do. The words we choose are as important as, if not more important than, the graphics that frame them. Here are four simple rules you can apply to instantly improve the usability of your touchscreen interfaces.
Use verbs to clearly describe what a button does. A non-specific label is confusing to the user and could require you to spend more time on training and support. “OK” and “Cancel,” or, even worse “Yes” and “No,” force the user to first fully understand the accompanying message and its context.
Put the emphasis on the first 12 characters of your messages and labels. People skim text. Expect a user to read only the first two or three words of any line. “You are about to shut down your system!” loses its impact if the user sees only the first 12 characters: “You are abou”. “Shutting down your system!” communicates the same message and truncates better.
A button’s label should be placed on the button itself rather than adjacent to it. Most designers center the text. But users tend to touch only the bottom half of a button — so consider placing the label above the center. This will increase its visibility while the user is touching it.
Eliminate duplication. If you use the same words over and over again on your button labels, group them together, instead, within a single labeled group — or eliminate the duplicate words altogether. This will make it much easier for your user to quickly locate and touch the action he wants to take.
You won’t be able to follow all of these rules all the time, but by doing so whenever possible, you’ll be delivering the best possible user experience.