The system should always keep users informed about what is going on, through appropriate feedback within a reasonable amount of time.

The system should speak the users’ language, with words, phrases, and concepts familiar to the user, rather than system-oriented terms. Follow real-world conventions, making information appear in a natural and logical order.

Users often choose system functions by mistake and will need a clearly marked “emergency exit” to leave the unwanted state without having to go through an extended process. Support undo and redo.

Users should not have to wonder whether different words, situations, or actions mean the same thing. Follow platform conventions and established design patterns.

Even better than good error messages is a careful design that prevents a problem from occurring in the first place. Eliminate error-prone conditions or check for them and present users with a confirmation option before they commit to the action.

Minimize the user’s memory load by making objects, actions, and options visible. The user should not have to remember information from one part of the interface to another.

Accelerators—unseen by the novice user—may often speed up the interaction for the expert user so that the design can cater to both inexperienced and experienced users. Allow users to tailor frequent actions.

Interfaces should not contain information that is irrelevant or rarely needed. Every extra unit of information in an interface competes with the relevant units of information and diminishes their relative visibility.

Error messages should be expressed in plain language (no codes), precisely indicate the problem, and constructively suggest a solution.

Even though it is better if the system can be used without documentation, it may be necessary to provide help and documentation. Any such information should be easy to search, focused on the user’s task, list concrete steps to be carried out, and not be too large.