Away from past controversial presentations, a matter of fact, intuitive and simplified approach to the Theory of Sampling (TOS) sampling variance prediction formula is offered which gives an insight on the type of model required for the liberation factor, the practical limitations of such model and methodological principles for its calibration._x000D_
This paper intends to see what happens in TOS when trying to go from the very simple towards the full level of real life complexity, and actually tries to answer the question: Is there such a thing as a simple' TOS?