260
and in particular an intensional definition,
1
which is “preferable to other types of
definitions and should be used whenever possible as [it] most clearly reveal[s] the
characteristics of a concept within a concept system” (ISO, 2009: 6.2). This
Appendix proposes a basic concept system of measurement with weaker terminological constraints, which allows us to provide for each relevant concept a term and
a characterization, sometimes in the form of explanation rather than a definition,
2
thus summarizing what is presented and discussed in the book.
As is common in top-level/upper ontologies, we use the term “entity” to refer to
the most generic concept, hence as a synonym of “object” in the sense of ISO
1087-1:2000: 3.1.1: “anything perceivable or conceivable”, so as to make it possible
to use “object” for any entity that carries a property (hence in this sense properties
are entities but are not objects). Together with “entity”, many other non-measurement-specific terms are used here with their usual meaning.
1 A structural strategy for building a concept system is top-down: some generic concepts are
assumed without a definition—called “primitive concepts” or simply “primitives”—and other concepts are subsequently derived from them according to a conjunctive logic:
X Y
Y n
:=
…
1 and
and
where the set {Y i } of the defining concepts is called the intension of the defined concept X. For
example, the VIM definition of , “process of experimentally obtaining one or more
values that can reasonably be attributed to a quantity” (JCGM, 2012: 2.1), can be understood as a
rephrasing of the following: measurement (X) is a process (Y 1 ) and (the process) is an experimental
obtainment of values (Y 2 ) and is a reasonable attribution of (these) values to a quantity (Y 3 ), i.e., X
≔ Y 1 and Y 2 and Y 3 . Evidently, for such a definition to be well formulated the defining concepts
(, , ) must have been previously defined. In a concept system built according to this top-down
strategy, definitions are means of specification: through definitions the system is built by progressive knowledge specification, where the relation between the defined concept X and each of the
defining concepts Y i is then species-genus, or, according to the ISO standards on terminology
work, subordinate-superordinate (hence in the definition mentioned above is a
species/subordinate of the genus/superordinate : measurement is a (species of/kind of)
process). In an intensional definition (ISO, 2000: 3.3.2), one defining concept Y 1 is singled out as
the superordinate, with the remaining Y 2 , …, Y n being its delimiting characteristics (ISO, 2000:
3.2.7). This leads to the template
defined concept superordinate concept
d elimiting
such that
:=
c characteristics
that can be read as
X
Y
Y
Y n
is a
such that
and
and
1
2
⊃
so that, for example, a measurement (X) is a process (Y 1 ) such that it is an experimental obtainment of values (Y 2 ) and is a reasonable attribution of these values to a quantity (Y 3 ).
2 In particular, the explanations in this concept system allow some circularities; that is, the explanation of the concept X includes a reference to the concept Y, and the explanation of Y includes a
reference to X. The substitution principle forbids this in a definition (ISO, 2009: 6.3.4). In other
words, these explanations include both a (n informal) definition and some possible notes.
Appendix A: A basic concept system of measurement
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