**8.4 Existence and consequences of a paradox**

Not all the difficulties have been resolved, however. In view of the difficulties arising in the field situations, the verdict of reality suggests the potential existence of future obstacles. We will make the assumption, currently only supported by observations, that application of this toolbox depends on a cognitive map and that the map is a simplified representation of the reality of field data, which remain complex.

It is therefore not unreasonable to mention the underlying existence of a paradox for the decision-makers. Since [12] they are all scientists, engineers and high-level technicians experienced in traditional scientific procedures, they will seek to be objective in the decisional choices by applying, naturally one might say, the PEO via the cognitive map to data which are above all complex and dynamic. This paradigmatic tool, imported from the experimental paradigm, too fixist and too simplified and which, finally, provides quality (objectivity) but which in these situations considerably limits the validity. The PEO proves to be poorly adapted to the characteristics of complex systems.
