The Effects of Alarm Mistrust and Signal Duration on Alarm Reactions and Perception of Alarm Validity

Researchers have begun examining variables that may moderate the degrading effects of alarm mistrust on alarm reaction performance. We examined alarm systems of varying reliability levels (60 or 80 percent true alarms) that generated either short or long duration alarms. We studied the impact of these variables on participant response frequency and perception of signal validity. The researchers sampled 40 Old Dominion University psychology students. We predicted that participants would rate long duration alarm signals as more representative of a valid signal. We also believed that participants would use the representativeness heuristic as a response strategy. The results partially supported our hypotheses. Participants rated the long duration signals as significantly more representative of a valid signal (p<.001). However, although participants responded significantly more often to long duration alarms (p<.01), participants in the 80% reliability group responded to significantly more alarms than those in the 60% reliability group (p=.02). The performance results are inconsistent with our hypothesis. Although participants perceived the long duration alarms to be more representative than the short, they did not base their response strategy entirely on alarm representativness. Despite these unexpected findings, the results suggest that alarm signal duration has a significant impact on alarm response frequency. Therefore, designers of complex systems may be able to moderate response degradation due to unreliability by designing systems that generate long duration alarm stimuli.