  We propose and develop the thesis that the quantum theoretical description of
experiments emerges from the desire to organize experimental data such that the
description of the system under scrutiny and the one used to acquire the data
are separated as much as possible. Application to the Stern-Gerlach and
Einstein-Podolsky-Rosen-Bohm experiments are shown to support this thesis.
General principles of logical inference which have been shown to lead to the
Schr\"odinger and Pauli equation and the probabilistic descriptions of the
Stern-Gerlach and Einstein-Podolsky-Rosen-Bohm experiments, are used to
demonstrate that the condition for the separation procedure to yield the
quantum theoretical description is intimately related to the assumptions that
the observed events are independent and that the data generated by these
experiments is robust with respect to small changes of the conditions under
which the experiment is carried out.
