Warning and Error Messages
Warning and error messages appear when a problem or error has occurred.
Warning dialogs should be:
- Understandable: Phrase your messages clearly, in non-technical terms and avoid obscure error codes.
- Specific instead of general: If the message is reporting a problem concerning a specific object or application, use the object or application name when referring to it.
- Informative and constructive: Tell the user the reason for a problem and help on how to solve the problem.
- Polite, non-terrifying and non-blaming: Avoid wording that terrifies the user ("fatal", "illegal"), blames him for his behavior, and be polite.
- To close a warning or error message that does not require further user interaction, provide a Close button. Do not use an OK button. Users may get confused if they are asked to confirm an error.
- Use buttons which match the type of statement or question made in the warning or error message. For example, do no ask a Yes/No question but then provide OK/Cancel buttons.
- When the user must choose between two actions to continue, use descriptive button labels instead of standard Yes/No or OK/Cancel buttons. For example, if the user must choose to continue or stop an action, provide the buttons "Continue" and "Cancel".
Details on demand
- Provide only a short error message and complement it by a Details button that provides more a detailed explanation in the same error dialog.
- If it makes sense for this kind of error, link from the error dialog to the corresponding page in the help system. Provide a Help button then.
Which widget to use
- Use dialogs for critical error messages, and when you need to make sure that the user sees the message.
- Use info panels for non-critical messages which do not require any further user interaction (typically dialogs with a single "OK" or "Close" button).