Features of an alarm affecting its usefulness:
(1) relation to true emergency or condition requiring attention (appropriate)
(2) frequency encountered
(3) intrusiveness of the warning
Hazards associated with a false alarm:
(1) The alarm is ignored entirely.
(2) There is a delay in response or people turn off the alarm without further investigation.
(3) An intrusive alarm may act as a distraction that interferes with other tasks.
(4) The user tampers with the device or system to inactivate or silence the alarm.
Reasons why the alarm may be ignored:
(1) New people are told to ignore the warning (cultural).
(2) The alarm is viewed as a nuisance.
(3) People become habituated to it and no longer pay heed to it.
The immediate impact of the false alarm can be rated based on its frequency and the severity of problems caused:
rating factor =
= (frequency of false alarm) * (problems associated with the false alarm)