I think Robert's text needs a bit more background. Would someone try?

Multiple instantiation is fundamental to the CRM and semantic models. Not just a technique.

We also observe that programmers writing code for selecting applicable properties as data entry into RDF/OWL based systems or mapping systems use to forget multiple instantiation, and to alert users that a suitable subclass may have the property needed.
It's not only a problem with other kinds of data models.



On 12/11/2018 1:42 PM, Christian-Emil Smith Ore wrote:
I like Robert's text. I can see some problems with the use of "merged classes" since there is a large number of possible classes. A "merged" class is simply a way to reformulate same as at the class level.

In a relational datebase one would need a common series of identifier for  the primary key in all involved tables which is uncommon but ok since one in principle need only one sequence giving unque identifers for an entire database (or all databases in the world)

From: Crm-sig <crm-sig-bounces@ics.forth.gr> on behalf of Detlev Balzer <db@balilabs.de>
Sent: 11 December 2018 12:16
To: crm-sig@ics.forth.gr
Subject: Re: [Crm-sig] Using multiple instantiation

I'm also wondering if we actually need such explanation. If the concern is that

many implementations at their core are not natively RDF or even graph-based and would run into difficulties trying to create relationship representations or classes in an object oriented programming language that instantiated multiple ontological classes.
then this is certainly true for "classical" relational databases without any level of object-relational mapping. However, anyone embarking on a certain degree of object-oriented design will be (or soon become) aware of these limitations, and of the various solutions discussed at length in the developer community.


Am 11.12.2018 um 11:23 schrieb Richard Light:

Unless I have misunderstood, both versions came from Robert. I still think that we need to consider what actually needs to be in the RDF document. In my view it should be the absolute minimum to 'do the job': the only question is what 'the job' should be. :-)


 Dr. Martin Doerr
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