Write Clear Text and Messages 575

Step 8: Write Clear Text and Messages 575

–– If a message allows initiation of an action to correct the situation described, • Include a properly labeled button initiating the corrective action. –– If a message describes an interrupted process whose state cannot be restored, • Provide a Stop button. –– If a message offers an opportunity to cancel a process as well as to perform or not perform an action, • Provide a Cancel button.

–– If more details about a message topic must be presented, • Provide a Help button. –– Designate the most frequent or least destructive option as the default. –– Display a message box only when the window of an application is active. –– Display only one message box for a specific condition.

Close box: –– Enable the title bar Close box only if the message includes a Cancel button.

Command buttons.

A user response to a message box is usually accomplished

though a command button. The kind, or kinds, of command buttons included depend upon the reason the message box was presented. If a message requires no user choices to be made but only an acknowledgment of the message, include an OK button. If the message requires the user to make a choice, include a command button for each option. Include OK and Cancel buttons only when the user has the option of continuing or stopping the action. Use Yes and No buttons when the user must decide how to continue. If these choices are too ambiguous, label the command buttons with the names of specific actions to be performed (Save and Delete, for example).

If a message allows initiation of a user action to correct the situation described, include a properly labeled button initiating the corrective action. If, for example, the message indicates that the user must switch to another application window to take corrective action, include a button that opens that application window. Be sure to clearly label the button and the results the user can expect from pressing it. If a message describes an interrupted process whose state can- not be restored, provide a Stop button. (Cancel implies restoring the state of the process or task that initiated the message.) If a message offers an opportunity to cancel a process as well as to perform or not perform an action, provide a Cancel button. Clearly label the button and the results the user can expect from selecting it. If more details about a message topic must be presented, provide a Help but- ton. This enables the message text to be succinctly presented.

Designate the most frequent or least destructive command option as the default. Because a message box disrupts the user’s current task, it is best to dis- play a message box only when the window of the application to which the mes- sage refers is active. If the application’s window is not active, use the application’s button entry on the taskbar to alert the user. After the user activates the application, the message box can be displayed. Display only one message box for a specific condition. Displaying a sequential set of message boxes tends to confuse users.

576 Part 2: The User Interface Design Process

Command buttons allow the message box interaction to be simple and effi- cient. If other types of controls are considered, always be aware of the potential increase in interface complexity.

Close box. Enable the title bar Close box only if the message includes a Cancel but- ton. To leave it available in other situations can confuse users.