“…This comes across clearly as soon as authors present their reasons for proposing several interfaces and display techniques: the Configural Display, which ''represents high-level constraints of the domain through the relationship among the low-level data that define the constraint'' (Bennett et al, 1993, p. 72). Thus, the polar star (Woods, Wise & Hanes, 1981) integrates the values of more than 100 sensors to represent the state of the process; the Representation Aiding Technique which, to assist anticipation behaviour, proposes helping the operator to assess ''where the level is, what factors are influencing the level (Shrink/swell vs. changes in the mass balance), and where the level will go given these influences and possible interventions'' (Bennett et al, 1993, p. 77); the Compensated Steam Generator Level put forward by Bennett, Woods and Haley (1986) is closely related to the higher levels of the abstraction hierarchy, although this technique is traditionally considered as a product of the representation aiding technique; the Integral Display or Object Display is also an example of this logic (Carswell Adapthya, Klaver, Kancler, Dolan & Wickens, 1987;Jones, Wickens & Deutsh, 1990;Elvers, et al 1993).…”