Monitoring refers to decision makers' tracking of key system variables as they work toward arriving at a decision.
Control refers to the decision maker's generation, evaluation and selection of alternative actions.
In real-time tasks, these two activities compete for the same attentional resources. Our findings show that some kinds of cognitive support degrade performance, rather than enhancing it. These results indicate that providing support for real-time dynamic decision making may be very difficult, and that designing effective decision aids requires a detailed understanding of the underlying cognitive processes.