What happens to human performance when a highly reliable automated system is passively monitored?

When humans are engaged in passive monitoring of a highly reliable automated system, research indicates that their performance tends to deteriorate over time. This phenomenon occurs because passive monitoring can lead to complacency and a reduction in the operator's engagement with the task. As the system operates automatically and reliably, there may be a decline in vigilance, situational awareness, and the skill sets necessary to intervene effectively should the automated system encounter an unexpected issue.

Additionally, when operators become less active in the monitoring process, they may not maintain the same level of cognitive readiness or critical thinking that would be necessary for effective decision-making if a problem arises. This deterioration is not typically present in scenarios where operators are more actively engaged in the operation of the system, as active involvement tends to enhance cognitive engagement and performance. Therefore, the correct answer reflects a clear correlation between the nature of passive monitoring and its impact on human performance in contexts involving automated systems.