The terms skill, rule and knowledge based information processing refer to the degree
of conscious control exercised by the individual over his or her activities. Figure 1
contrasts two extreme cases. In the knowledge based mode, the human carries out a
task in an almost completely conscious manner. This would occur in a situation
where a beginner was performing the task (e.g. a trainee process worker) or where an
experienced individual was faced with a completely novel situation. In either of these
cases, the worker would have to exert considerable mental effort to assess the
situation, and his or her responses are likely to be slow. Also, after each control
action, the worker would need to review its effect before taking further action, which
would probably further slow down the responses to the situation.