The Interface Elements Chapter 4 - Menus Hierarchical Menus Hierarchical menus are menus that include a menu item from which a submenu descends. You can offer additional menu item choices without taking up more space in the menu bar by including a submenu in a main menu. When the user drags the pointer through a menu and rests it on a hierarchical menu item, a submenu appears after a brief delay. To indicate that a submenu exists, use a triangle facing right, as shown in Figure 4-36 .
Submenus add complexity to the interface.
They hide choices from people by adding a layer to menus. They are physically more difficult to use than menus that pull down from the menu bar. You should use a submenu only when you have more menus than fit in the menu bar. Figure 4-37 shows an example of unnecessary submenus. Figure 4-37 Don't use submenus unnecessarily When you use submenus, include them in a menu with a logical relationship to the choices they contain.