ABSTRACT
Toggle controls enable users to switch between two settings rapidly. Take the example of a light switch. Flip the switch up to turn the light on, and flip the switch down to turn it off. Another common type of toggle control is a single button that alternates between two states each time it is activated. For example, pressing the “Caps Lock” key on a keyboard causes all typed letters to be capitalized, while pressing the key a second time deactivates the feature. The ambiguity arises when a user cannot tell whether the toggle control’s label describes the current state or the function to be performed. Toggle ambiguity can lead people to deactivate functions that they wish to activate and vice versa. Such use errors could lead to disaster in many cases, such as the operation of life-sustaining medical equipment or of an airplane.
