The user interface of an application should be internally consistent, and consistent with related applications. An unfamiliar dialog box is easier to understand if its design is consistent with other dialog boxes in the application, related applications, or the host system. One example of this is the consistent placement of buttons such as OK and Cancel. The technique associated with each kind of tile—how you enter text in a text box and how you select a list box item—should also be consistent. The best way to achieve consistency is to reuse tiles and the code that controls them.
Standardization contributes to consistency. Use standard definitions for dialog box controls. This reduces your work, contributes to consistency, and makes it easier for users to learn and use your dialog boxes.
Use language that is clear. Although dialog boxes are considered part of a graphical interface, most of the tiles and information they present are textual. The labeling of dialog boxes, naming of buttons, and phrasing of messages should be direct and unambiguous. Avoid jargon and technical terms that users may not understand.