UI Rule of One

There should only be one primary action the user can take on the screen at a time. When there is more than one action to take it becomes confusing. Which should I do first (ordering)? Which am I supposed to do (decisions)?

As a simple analogy, think of the difference between a plane’s cockpit and a soap dispenser. The former is filled with knobs and switches for all sorts of functions, the latter has only one thing you can do—get soap.

If you want to make UI feel intuitive, requiring little to no explanation, distilling the interface into a series of single actions (choices) is your best bet.

That doesn’t mean there isn’t a place for more complicated interfaces, but if you see this happening, you’ll know it increases the level of understanding needed by new users.