Redundant Interface: An interface that
duplicates functionality provided by some other interface.
e.g.
Doorknobs that can be turned
clockwise or
counterclockwise to open the associated
door.
In Windows, being able to close an application by clicking on the X, selecting file|close, pressing alt-f4 or selecting End Task from the Close Program dialog.
Frequently, redundant interfaces are
taken for granted. Despite this, many
people will violently
oppose creation of a redundant interface. It is my
belief that redundant interfaces
allow people to choose the interface that seems most natural to them.