Pat Hayes wrote: (01)
> We need to distinguish the following from one another, whatever we
> call them.
>
> (1) the dimension that 'length' corresponds to, which is one-
> dimensional spatial extent. (This is also the dimension for 'width',
> 'height', 'distance', 'thickness', etc., so if these are distinct it
> must be in some other way than the dimension they identify.) (02)
I think this is the definition of 'length' as the 'kind of quantity'
(dimension). And that dimension is a classifier of 'particular
quantities' that are the lengths of specific things. (03)
> (2) the property Of a thing called its length. This should be
> conceptualized as a function or a property in a suitable formal
> description, ie it depends on the thing whose length is being measured. (04)
Agreed. This was not previously mentioned per se. (05)
> (3) the class of all possible lengths, ie values of the lengthOf
> property. This is a class or a predicate in a suitable formal
> description. Its the range of the lengthOf function. It is an element
> of the meta-class of measure classes. (06)
Yes. This is the length subclass of the class that I think is meant by
'magnitude of quantity'. (07)
> (4) the numerical value of a length, using some suitable measuring
> scale of lengths. I would suggest conceptulaizing a measuring scale as
> a function with domain a measure class and range some totally ordered
> measuring set, probably the reals or natural numbers in most cases,
> though other choices are possible for eg. approximate measurements. (08)
Yes. That is 'quantity value' in VIM. And we can get into the world of
quantity scales if we want to. (09)
>> Confusing them and breaking their language habits isn't particularly
>> helpful
>
> Not gratuitously, but if we are to write a coherent ontology we may be
> obliged to be pickier than many existing glossaries were designed to
> be. For example, we cannot confuse a property with a class, even if we
> use the same name for both of them. (010)
+1 (011)
With respect to Martin's concern, the point is that there is a set of
different concepts associated with the term 'length', but we know
exactly what that set is. And we need all of those concepts. But our
language rules will not permit them all to be called 'length' with no
further adornment, because it will confuse both the readers and the tooling. (012)
-Ed (013)
--
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 (014)
"The opinions expressed above do not reflect consensus of NIST,
and have not been reviewed by any Government authority." (015)
_________________________________________________________________
Message Archives: http://ontolog.cim3.net/forum/uom-ontology-std/
Subscribe: mailto:uom-ontology-std-join@xxxxxxxxxxxxxxxx
Config/Unsubscribe: http://ontolog.cim3.net/mailman/listinfo/uom-ontology-std/
Shared Files: http://ontolog.cim3.net/file/work/UoM/
Wiki: http://ontolog.cim3.net/cgi-bin/wiki.pl?UoM_Ontology_Standard (016)
|