A typical confirmation.
Confirmations have these essential characteristics:
• They are displayed as the direct result of an action initiated by the user.
• They verify that the user wants to proceed with the action.
• They consist of a simple question and two or more responses.
Confirmations are most useful when the action requires the user to make a relevant and distinct choice that can't be made later. That choice often involves some element of risk that isn't obvious to the user, but risk isn't essential to confirmations. These elements are necessary to justify the interruption of responding to a modal dialog.
By contrast, warning messages present a condition that might cause a problem in the future. Their fundamental characteristic is that they involve risk:
• They involve potential loss of one or more of the following:
o A valuable asset, such as data loss or financial loss.
o System access or integrity.
o Privacy or control over confidential information.
o User's time (a significant amount, such as 30 seconds or more).
• They have unexpected or unintended consequences.
• They require correct handling now because mistakes can't be easily fixed, and may even be irreversible.
If a confirmation involves risk, it can be considered a warning as well. Consequently, the warning message guidelines also apply.