Principle Five: Tolerance for Error

T he design minimizes hazards and the adverse consequences of accidental or unintended actions.

Guidelines:

•  Arrange elements to minimize hazards and errors: most used elements, most accessible hazardous elements eliminated, isolated, or shielded.

•  Provide warnings of hazards and errors.

•  Provide fail safe features.

•  Discourage unconscious action in tasks that require vigilance.

Example: "undo" button on computer word-processing program