Manual override

A manual override is a mechanism wherein control is taken from an automated system and given to the user. For example, a manual override in photography refers to the ability for the human photographer to turn off the automatic aperture sizing, automatic focusing, or any other automated system on the camera.

Some manual overrides can be used to veto an automated system's judgment when the system is in error. An example of this is a printer's ink level detection: in one case, a researcher found that when he overrode the system, up to 38% more pages could be printed at good quality by the printer than the automated system would have allowed.

Automated systems are becoming increasingly common and integrated into everyday objects such as automobiles and domestic appliances. This development of ubiquitous computing raises general issues of policy and law about the need for manual overrides for matters of great importance such as life-threatening situations and major economic decisions. The loyalty of such autonomous devices then becomes an issue. If they follow rules installed by the manufacturer or required by law and refuse to cede control in some situations then the owners of the devices may feel disempowered, alienated and lacking true ownership.

Examples in fiction

As a plot device manual override is often used in Sci-Fi because of the usual prevalence of advanced / electronic technology. For example:

• In Star Trek many automatic systems, such as the automatic navigation, or the 'site-to-site transporter' can be overridden. A slightly different type of manual override is used in the film Star Trek: Insurrection, when acting Captain of the Starship Enterprise (E) William Riker asks the computer for the 'manual command column', in effect a joystick which gives him pilotage control of the ship.
• In Casino Royale (2006), a villan overrides the emergency fire sprinklers at Miami airport and starts a distraction so that he can blow up a plane with a remote-controlled pipe bomb.