Mike Bennett wrote: (01)
> That sounds great. Can you generate it from the output of a UML model?
> How does it compare with what I've done at
> www.hypercube.co.uk/edmcouncil which aims to fulfil that exact same
> requirement from within UML but is by no means perfect?
>
> Mike
> (02)
>>> [EB] The trick is not to be excessively geeky. My late mentor, Dr. Selden
>>> Stewart, once observed that all modeling languages are BLAs -- boxes,
>>> lines and annotations. As long as you stick with class boxes/balls,
>>> association/property lines/wires, and text labels (annotations), you
>>> don't violate the "anti-technical" prejudices of "business persons".
>>>
>> [MW] OK. If that is your objective then I will throw what was originally (as
>> far as I know) the CDIF (CASE Data Interchange Format) notation into the
>> ring. This consists of named boxes for classes/entity types and named arrows
>> for relationships/relations, where the direction of the arrow tells you
>> which direction to read the relationship name in (and nothing else). So you
>> could have:
>>
>> A --part of--> B, or
>> A <--has part-- B
>>
>> My experience is that this notation is not only very simple, but very easy
>> for anyone to read. (03)
Indeed. Three points: (04)
(1) This is essentially the notation one sees in Protegé. And you can
clearly generate a very similar notation with a UML tool, by
a) making one end of the association non-navigable, and
b) naming the other, or naming the association by the verb
This is in fact common practice for people modeling Java in UML. The
advantage of UML tools, including some free ones, over Powerpoint and
Visio is that they generate a (more or less) standard machine-readable
XML form, which can be converted to OWL, for example, with some readily
hacked tool. (I already have 3 or 4 such things.) The advantage of
Protegé is that it can generate OWL and a proprietary axiomatic text
form (which we could also hack). (Student projects) (05)
(2) I stand by my claim that the audience for the would-be standard is
knowledge engineers, not business people. If we lose sight of that, we
will find ourselves making a weak and deliberately inaccurate ontology,
because "business people don't understand concept X that way" or
"business people won't understand such a complex model". (I have
recently worked with a group like that, and it wasted two years of my
time.) So the graphical model is a sketch of the ontological
relationships, which should be _correct_, but not necessarily
"complete". We must stand by the Einstein razor: "We should make things
as simple as possible, but no simpler." (06)
(3) Matt doesn't mention the CDIF notation for "subtype"/subsumption.
This is a foundational concept in OWL, and it is very important to
modeling measurement concepts. In particular, every 'measurement unit'
is_a 'quantity'. I would be wary of a notation like:
measurement-unit -- is a --> quantity
because it makes the notation ambiguous. 'is_a' is a class-to-class
relationship, rather than an instance-to-instance relationship (like
'part of'). It models an axiom, not just a relation. That is:
A -- is part of --> B
models a relation "is part of" whose domain is things that satisfy
relation (class) A, and whose range is things that satisfy relation B --
a vocabulary item. It has two free variables. Whereas,
A -- is a --> B
models a proposition, a statement: Every A is a B. Formally,
(forall x) (if (A x) (B x))
It has no free variables. And the model asserts that proposition,
making it an axiom.
So I would object to overuse of the arrow notation, if it leads to such
an ambiguity. (07)
And finally, I did say that we need a language-selection committee. I
didn't volunteer to lead it, precisely because we need some persons with
more knowledge of the ontological Tower of Babel. We seem to have
volunteers in the persons of Messrs. West, Bennett, and Walker. ;-) (08)
-Ed (09)
--
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 (010)
"The opinions expressed above do not reflect consensus of NIST,
and have not been reviewed by any Government authority." (011)
_________________________________________________________________
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 (012)
|