Rijgersberg, Hajo wrote:
> Dear all,
>
> Please allow me to make a remark about quantity kinds. Hopefully this
>discussion is appreciated; it is solely meant to be constructive, with the aim
>of working together to achieve a high-quality vocabulary.
>
> Let me get to the point. I think we should not define a separate class
>"quantity kind". "Kind" is an implicit part of the ontology language; classes
>are meant to model "kinds". We should not deviate from this principle, but
>exploit it.
>
> So not, for example:
>
> "length of my table" ---"has quantity kind"---> "length"
> "length of my table" ---"is a"---> "quantity"
> "length" ---"is a"---> "quantity kind"
>
> but:
>
> "length of my table" ---"is a"---> "length (quantity)"
> "length (quantity)" ---"is a"---> "quantity"
>
The problem is that we wish to call out certain subtypes of "quantity"
as having interesting properties. For example, "unit of measure" -- "is
a" -- "quantity"
but NOT "unit of measure" -- "is an instance of" -- "quantity kind"
Every "quantity kind" is not only a subtype of quantity, but it must
also satisfy: If K is a "quantity kind" and x and y are any two
instances of K, then x and y are comparable. (01)
A 'quantity kind' is a classifier whose instances are classifiers of
quantities (ontological 'kind's of quantity) that also satisfy the above
requirement. If you find the use of 'kind' to be confusing in this
regard, we could call it a 'quantity frazbot', but VIM uses the term
"kind of quantity" with this intent. (02)
-Ed (03)
'When I use a word,' Humpty Dumpty said in rather a scornful tone,
'it means just what I choose it to mean--neither more nor less.'
-- Lewis Carroll (C.L. Dodgson), "Through the Looking Glass" (04)
--
Edward J. Barkmeyer Email: edbark@xxxxxxxx
National Institute of Standards & Technology
Manufacturing Systems Integration Division
100 Bureau Drive, Stop 8263 Tel: +1 301-975-3528
Gaithersburg, MD 20899-8263 FAX: +1 301-975-4694 (05)
"The opinions expressed above do not reflect consensus of NIST,
and have not been reviewed by any Government authority." (06)
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