False alarm
Encyclopedia
A false alarm
, also called a nuisance alarm, is the fake report of an emergency, causing unnecessary panic and/or bringing resources (such as emergency services) to a place where they are not needed. Over time, repeated false alarms in a certain area may cause occupants to start to ignore all alarms, knowing that each time it will probably be false. The concept of this can be traced at least as far back as Aesop
's story of The Boy Who Cried Wolf
, where many episodes of a boy falsely yelling "wolf" caused the townspeople to ignore his cries when a real wolf came. In addition, false alarms have the potential of diverting emergency responders away from legitimate emergencies, which could ultimately lead to loss of life.
In industrial
alarm management
, a false alarm could refer either to an alarm with little information
content that can usually safely be eliminated, or one that could be valid but is triggered by a faulty instrument. Both types are problematic because of the "cry wolf" effect described above.
The term "false alarm" is actually a misnomer, and is regularly replaced by the term "nuisance alarm." When a sensor operates, it is hardly false, and it is usually a true indication of the present state of the sensor. A more appropriate term is nuisance, indicating that the alarm activation is inconvenient, annoying, or vexatious. A prime example of this difference is burglar alarm
s being set off by spiders. (A spider crawling on a web in front of the motion detector appears very large to the motion detector.)
One tragic example of the consequences of continued false alarms was at Boland Hall
at Seton Hall University
on January 19, 2000. Months of false fire alarms caused many students to start ignoring the fire alarms. However when an actual fire broke out, three students who ignored the fire alarms died and many others suffered injuries.
Likewise, after too many audible car alarm
s are found false, most people no longer pay attention to see whether someone is stealing a vehicle, so even certain experienced thieves may confess that these alarms would not deter them from stealing vehicles.
Intentional false alarms of any kind, especially through emergency notification systems, are very serious criminal offenses, and can result in very severe legal punishments.
, a false alarm occurs where a non-target event exceeds the detection criterion and is identified as a target (see Constant false alarm rate
).
False alarms could also refer to situations where one becomes startled about something that is later determined to be untrue.
Alarm
An alarm device or system of alarm devices gives an audible or visual alarm signal about a problem or condition.Alarm devices include:* burglar alarms, designed to warn of burglaries; this is often a silent alarm: the police or guards are warned without indication to the burglar, which increases...
, also called a nuisance alarm, is the fake report of an emergency, causing unnecessary panic and/or bringing resources (such as emergency services) to a place where they are not needed. Over time, repeated false alarms in a certain area may cause occupants to start to ignore all alarms, knowing that each time it will probably be false. The concept of this can be traced at least as far back as Aesop
Aesop
Aesop was a Greek writer credited with a number of popular fables. Older spellings of his name have included Esop and Isope. Although his existence remains uncertain and no writings by him survive, numerous tales credited to him were gathered across the centuries and in many languages in a...
's story of The Boy Who Cried Wolf
The Boy Who Cried Wolf
The Boy Who Cried Wolf, is one of Aesop's Fables, numbered 210 in the Perry Index. From it is derived the English idiom 'to cry wolf', meaning to give a false alarm.-The fable and its history:...
, where many episodes of a boy falsely yelling "wolf" caused the townspeople to ignore his cries when a real wolf came. In addition, false alarms have the potential of diverting emergency responders away from legitimate emergencies, which could ultimately lead to loss of life.
In industrial
Industry
Industry refers to the production of an economic good or service within an economy.-Industrial sectors:There are four key industrial economic sectors: the primary sector, largely raw material extraction industries such as mining and farming; the secondary sector, involving refining, construction,...
alarm management
Alarm management
Alarm management is the application of human factors along with instrumentation engineering and systems thinking to manage the design of an alarm system to increase its usability...
, a false alarm could refer either to an alarm with little information
Information
Information in its most restricted technical sense is a message or collection of messages that consists of an ordered sequence of symbols, or it is the meaning that can be interpreted from such a message or collection of messages. Information can be recorded or transmitted. It can be recorded as...
content that can usually safely be eliminated, or one that could be valid but is triggered by a faulty instrument. Both types are problematic because of the "cry wolf" effect described above.
The term "false alarm" is actually a misnomer, and is regularly replaced by the term "nuisance alarm." When a sensor operates, it is hardly false, and it is usually a true indication of the present state of the sensor. A more appropriate term is nuisance, indicating that the alarm activation is inconvenient, annoying, or vexatious. A prime example of this difference is burglar alarm
Burglar alarm
Burglar , alarms are systems designed to detect unauthorized entry into a building or area. They consist of an array of sensors, a control panel and alerting system, and interconnections...
s being set off by spiders. (A spider crawling on a web in front of the motion detector appears very large to the motion detector.)
One tragic example of the consequences of continued false alarms was at Boland Hall
Boland Hall Fire
The Boland Hall fire was a fatal fire in Boland Hall, a freshman residence hall on the Seton Hall University campus in South Orange, New Jersey, United States on January 19, 2000. Three students died and many more were injured. It was one of the deadliest college fires in recent U.S...
at Seton Hall University
Seton Hall University
Seton Hall University is a private Roman Catholic university in South Orange, New Jersey, United States. Founded in 1856 by Archbishop James Roosevelt Bayley, Seton Hall is the oldest diocesan university in the United States. Seton Hall is also the oldest and largest Catholic university in the...
on January 19, 2000. Months of false fire alarms caused many students to start ignoring the fire alarms. However when an actual fire broke out, three students who ignored the fire alarms died and many others suffered injuries.
Likewise, after too many audible car alarm
Car alarm
A car alarm is an electronic device installed in a vehicle in an attempt to discourage theft of the vehicle itself, its contents, or both. Car alarms work by emitting high-volume sound when the conditions necessary for triggering are met, as well as by flashing some of the vehicle's...
s are found false, most people no longer pay attention to see whether someone is stealing a vehicle, so even certain experienced thieves may confess that these alarms would not deter them from stealing vehicles.
Intentional false alarms of any kind, especially through emergency notification systems, are very serious criminal offenses, and can result in very severe legal punishments.
Other uses
In (signal) detection theoryDetection theory
Detection theory, or signal detection theory, is a means to quantify the ability to discern between information-bearing energy patterns and random energy patterns that distract from the information Detection theory, or signal detection theory, is a means to quantify the ability to discern between...
, a false alarm occurs where a non-target event exceeds the detection criterion and is identified as a target (see Constant false alarm rate
Constant false alarm rate
Constant false alarm rate detection refers to a common form of adaptive algorithm used in radar systems to detect target returns against a background of noise, clutter and interference.Other detection algorithms are not adaptive...
).
False alarms could also refer to situations where one becomes startled about something that is later determined to be untrue.
See also
- Bomb threatBomb threatA bomb threat is generally defined as a threat, usually verbal or written, to detonate an explosive or incendiary device to cause property damage, death, or injuries, whether or not such a device actually exists...
- Burglar alarm#Enhanced Call Verification
- Culture of fearCulture of fearCulture of fear is a term used by certain scholars, writers, journalists and politicians who believe that some in society incite fear in the general public to achieve political goals, for example......
- Emergency evacuationEmergency evacuationEmergency evacuation is the immediate and rapid movement of people away from the threat or actual occurrence of a hazard. Examples range from the small scale evacuation of a building due to a bomb threat or fire to the large scale evacuation of a district because of a flood, bombardment or...
- False positive
- Fire alarm
- Battle of Los AngelesBattle of Los ÁngelesThe Battle of Los Ángeles was a military action fought on March 22, 1880 between the Chilean and Peruvian armies during the Tacna and Arica Campaign of the War of the Pacific...