Result range
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<section begin=glossary />
- The domain of a variable contains all possible values that the result of the variable may get with probability P>0. The domain is restricted by logical (the number of actual individuals must be an integer), rational (concentration cannot be negative or above 1000 g/kg), and observational (TCDD concentration in humans has never been observed to be above 144000 ng/kg fat) statements.
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Should 'Domain' be a sub-attribute of 'Definition' in a variable? Alternative solution: it is discussed under 'Data', because in practice, the domain is based on Data. Third alternative: it is put under 'Result', maybe as a sub-attribute; this is not a good idea, because the domain has implications on e.g. 'Formula', and it is not good if the result affects Definition.
- → Because clear understanding does not yet exist, the attribute structure is not changed, and the domain is described under 'Data'.
Scope
How can a plausible domain for a variable be found? What are the criteria for inclusion or exclusion of a particular value or range?
Definition
Rationale
In expert judgement, it is a common practice to define the domain by calculating the difference between the fractiles 0.05 and 0.95, extend that by k % (k is often 10 % or found by optimising), and subtract it from and add it to the fractiles 0.05 and 0.95, respectively.
In open assessment, all values are included in the domain by default. A suggested procedure is to exclude any range X that passes a critical argumentation about the exclusion. The argumentation has a statement of the following form: "It is impossible that the result of the variable may be within range X." If the statement is accepted, X is excluded from the domain. D↷
Procedure
All values are included in the domain by default. Any range X that passes a critical argumentation about the exclusion will be excluded. The argumentation has a statement of the following form: "It is impossible that the result of the variable may be within range X." If the statement is accepted, X is excluded from the domain.