as a factor to consider their response. Confidence in response also increased with increased functional dependency. Moreover, increased alarm numbers from two to four resulted in increased response rates. This increase in response rate occurred even when implicated system components were of low functional agreement. Results suggest that increased alarm numbers may override strategies that are based on their understanding of the system, and this consideration should be taken when designing complex alarm displays. Perhaps a confirmation bias is occurring, where during occasions containing low component agreement, participants tended to disregard that information in the presence of other active confirming alarms. This influence of increased alarm number on response further suggests a contextual influence, one which is perceptually based. Experience with responding was also shown to affect confidence in responses made, in that confidence increased between the first and second block of trials. This indicates that they were adopting a strategy or "understanding" of the system. This has training implications in that elevated confidence as a function of experience, regardless of receiving any meaningful feedback, could interfere with future performance. Results also revealed that those who rated themselves as more knowledgeable in automobile mechanics tended to have higher overall response confidence than the less knowledgeable. However, no differences in response strategies were found between more and less knowledgeable persons. These results clearly demonstrate the importance of understanding alarm context as well as cognitive influences for design of alarm displays as well as training application.
Bliss J. P., Gilson R. D., & Deaton J. E. ( 1995). Human probability matching behavior in response to alarms of varying reliability. Ergonomics, 38, 2300-2312.
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