Model Consistency

We dedicate this second block to the model consistency problem. We start with the problem of physical consistency by indicating that not all formulas are valid to represent a physical variable when written in terms of other basic variables. We formulate a consistency condition in terms of a functional equation and show the only valid form. Second, we discuss probability consistency and show that some proposed models are contradictory from the point of vie of probability theory. We define operation stable consistency and suggest the use of reproductive models when possible. Finally, we deal with extreme value consistency, providing some rules for dsatisfying this condition and indicating some common errors found in the literature when using extreme value models in engineering practice.