Individual ETTO rules

Erik Hollnagel

Ph.D., Professor, Professor Emeritus


Individual (psychological) ETTO rules

In addition to the work related ETTO rules, people also use ETTO rules to manage their own situation, e.g., in terms of workload or task difficulty. Such rules can be found for situations of information input overload, general ways of thinking and reasoning (cognitive style), as well as the various judgement heuristics.

  • Scanning styles – differences in the way in which assumptions are tested, either by conservative focussing where only one aspect is changed at a time or by focus gambling where more than one attribute is changed at a time.
  • Levelling versus sharpening – individual variations in the distinctiveness of memories and the tendency to merge similar events.
  • Reflection versus impulsivity – differences in the ways in which alternative hypotheses are formed and responses made.
  • Learning strategies – a holist gathers information randomly within a framework, while a serialist approaches problem-solving step-wise, proceeding from the known to the unknown.