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<br>
There is an interesting article here:<br>
<br>
<a class="moz-txt-link-freetext" href="http://www.cs.vu.nl/~guus/public/owl-restrictions/">http://www.cs.vu.nl/~guus/public/owl-restrictions/</a><br>
<br>
That discusses the differences between OWL and UML. <br>
<br>
One of the features of OWL that I like is the notion of a necessary and
sufficient properties but alas this is lacking in UML. Sufficient
conditions allow you to determine if an instance is a member of a class
when it in not explicitly stated. You can therefore receive and object
and work out what it is according to an ontology of your choice - which
seems pretty useful to me. It is a mechanism, I believed, could enable
us to integrate a simple core ontology with more complex specialist
ontologies that some network participants may choose to use. It is not
available in UML but could be used to reason about a UML ontology
expressed in OWL or RDFS.<br>
<br>
OWL doesn't do qualified cardinality restrictions as well as UML - but
there are work rounds and proposals and I am not sure how important
this is.<br>
<br>
There is also a good quote in the article on data modeling versus
building ontologies:<br>
<br>
"A data model is a model of the information in some
restricted well-delimited application domain, whereas an ontology is
intended to provide a set of shared concepts for multiple users and
applications. To put it simply: data models live in a relatively small
closed world; ontologies are meant for an open, distributed world
(hence their importance for the Web)."<br>
<br>
I think we are sometime confusing the two in our discussions.<br>
<br>
Bottom line is:<br>
<ul>
<li>You can't express everything in UML or OWL.<br>
</li>
<li>If we want to assure that we can swap between two or more
modeling languages then we can't use all the feature of any of them but
have to come up with a subset.</li>
</ul>
The answer never includes a single TLA. <- apart from this answer!<br>
<br>
My personal feeling is that anything that is defined centrally by TDWG
should use the lowest common denominator of features anyhow.<br>
<br>
As usual I am grateful for you comments/thoughts.<br>
<br>
Roger<br>
<br>
<br>
<br>
<br>
<br>
<br>
<pre class="moz-signature" cols="72">--
-------------------------------------
Roger Hyam
Technical Architect
Taxonomic Databases Working Group
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<a class="moz-txt-link-freetext" href="http://www.tdwg.org">http://www.tdwg.org</a>
<a class="moz-txt-link-abbreviated" href="mailto:roger@tdwg.org">roger@tdwg.org</a>
+44 1578 722782
-------------------------------------
</pre>
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