What are the five extrapolations from the definition of validity of a diagnosis?

The five extrapolations are: (a) validity can be presented at several levels or degrees; (b) it depends on the available evidence; (c) it depends on the underlying theory; (d) it is a property of the diagnosis and not of its components; and (e) it depends on the intended clinical use.

From the definition of validity of a diagnosis, five implications are drawn. First, validity is not all-or-nothing; it can be expressed in varying degrees. Second, validity rests on the quality and quantity of evidence supporting the diagnosis. Third, validity also relies on the theoretical framework that explains why the defining characteristics indicate the diagnosis. Fourth, validity attaches to the diagnosis as a whole interpretation, not to individual defining characteristics. Fifth, whether a diagnosis is valid depends on the specific clinical purpose for which it is used.