W3C home > Mailing lists > Public > public-owl-wg@w3.org > November 2007

Re: ISSUE-67 (reification): REPORTED: use of reification in mapping rules is unwise

From: Jeremy Carroll <jjc@hpl.hp.com>
Date: Fri, 23 Nov 2007 13:22:44 +0000
Message-ID: <4746D424.5060203@hpl.hp.com>
To: Alan Ruttenberg <alanruttenberg@gmail.com>
CC: Boris Motik <boris.motik@comlab.ox.ac.uk>, "'OWL Working Group WG'" <public-owl-wg@w3.org>

While 'hard requirement' is a better term than 'need' I am not sure that 
there are any such in an incremental release. OWL 1.1 will be as good as 
we can make it, within constraints.

I am happy that we have high wnats including:

- annotation of axioms
- a mapping of such annotations into RDF
- an OWL Full semantics of such mappings
- a change which is an incremental change over OWL 1.0, rather than a 
major change

I am currently far from convinced that all these desiderata can be met 
simultaneously. It is arguably unhelpful then to describe any of them as 
needs or even hard requirements. If we discover that something has to 
give, then if all of these are indeed hard requirements, we shall fail.


Alan Ruttenberg wrote:
> On Nov 21, 2007, at 6:40 AM, Boris Motik wrote:
>> Hello,
>> I don't want to get into an argument here whether this is really 
>> needed or not; however, I wanted to point out that I spoke to quite
>> a few people asking for the annotation of axioms.
> I concur that this is a hard requirement for OWL 1.1. It has come up 
> over and over again at OWLED.
>> There is yet another solution: we might have axiom annotations in the 
>> structural specification, but then disallow (or simply delete
>> them) when the ontology is exported into OWL RDF.
>  From my point of view, if some feature can't render in RDF, then they 
> might as well not be defined at all. Having a complete RDF rendering of 
> the full language would seem to me to also be a hard requirement.
> Regards,
> Alan
>>     Boris
>>> -----Original Message-----
>>> From: public-owl-wg-request@w3.org 
>>> [mailto:public-owl-wg-request@w3.org] On Behalf Of Jeremy Carroll
>>> Sent: 21 November 2007 11:37
>>> To: Boris Motik
>>> Cc: 'OWL Working Group WG'
>>> Subject: Re: ISSUE-67 (reification): REPORTED: use of reification in 
>>> mapping rules is unwise
>>> Boris Motik wrote:
>>>> Hello,
>>>> I actually really dislike reification myself; unfortunately, I don't 
>>>> see how to get around these
>>> issues in certain cases. The
>>>> problem is that sometimes you need more than binary associations 
>>>> between objects.
>>>> For example, consider the problem of annotating a SubClassOf axiom. 
>>>> In RDF, you write <x
>>> rdfs:subClassof y>. But you've just used
>>>> both x and y; there is no place for an annotation.
>>>> The only solution I see is not to use reification, but to introduce 
>>>> yet separate vocabulary and
>>> represent ternary relations more
>>>> explicitly. I am really open to any suggestions on this point, 
>>>> because I do see the point that
>>> reification is ugly.
>>>> Boris
>>> A different approach would be to decide that we cannot address the use
>>> cases for annotations of axioms yet, and to postpone related issues, and
>>> make do with the OWL 1.0 solution.
>>> Jeremy
Received on Friday, 23 November 2007 13:23:16 UTC

This archive was generated by hypermail 2.3.1 : Tuesday, 6 January 2015 21:42:00 UTC