Consistency is important both among applications and within a single application.
Consistency helps the user transfer familiar skills to new situations.
The user can apply the knowledge learned from one application to another application, reducing the amount of learning and subsequent recall. Consistency within applications facilitates exploration of new functions. When components work in a manner that is consistent with other components, the user will be less afraid to try new functions. The new functions will seem familiar, comfortable, and appropriate. For example, because Pulldown , Popup , and Option Menus are similar components, their operation and use should be similar.