Troubleshooting with an inaccurate mental model

In some fault-diagnosis situations, troubleshooters may misunderstand system structure and functioning. An experiment examined how a troubleshooter´s mental model of a logic network might prejudice the ability to diagnose previously unseen faults. In the knowledge acquisition phase, subjects inferred the structure of a logic network by viewing it in different states. Most subjects ended up with slightly inaccurate mental models of the network. In the fault-diagnosis phase, subjects were required to diagnose novel faults placed in the network. Two factors were varied in a 2×2 design: whether a subject believed a link existed or not, and whether the belief was true or false. Faults involved the addition of new links or the deletion of existing links. Subjects had difficulty diagnosing faults that involved links they believed did not exist and faults that influenced parts of the network about which they had false beliefs, and it was harder for subjects to see that something was wrong with the network if the fault involved a network link they believed not to exist. However, the ability to see the symptoms of the fault was not always a guarantee of correct fault diagnosis