Re: [OWLWG-COMMENT] ISSUE-55 (owl:class)

Mike - this is what I was responding to - while I think recommending  
everyone use owl:class is fine, and we essentially did it in OWL 1.0,  
the point is lots of people are using rdfs:class in a lot of large  
ontologies - OWL tools generally seem happy with this (making the  
change or reporting something to the user), however, there isn't a  
great deal of effort that I can see being made on the part of, for  
example, the FOAF community, to change to owl:class, and I don't see  
the motivation for them to do so, since they are in OWL Full  
anyway.   I believe most rdfs users would see little difference if  
they used OWL class, with the exception that in some cases it would  
mean bringing in the OWL namespace, and in other cases it would mean  
a lot of cleanup or reverse engineering w/o a lot of perceived gain.
  Your second suggestion (that OWL tools just make the fix) is okay  
by me, and actually I think it is the status quo, but doesn't really  
fix the problem for the user starting to create a new model - there's  
still confusion as to which to use.  What I hoped in this issue was  
that we could find a way to make owl:class owl:equivalentTo  
rdfs:class, but wishing for that didn't make it so, and the semantics  
of OWL DL 1.1 seem to make it impossible to go there.
  So while it's great that OWL tools could be able to handle  
rdfs:class, although Peter and Carsten seem to disagree (which I  
think is what you and Alan are trying to fix), I was just wishing  
there was a way to make it all come together - the rifts between OWL  
DL and OWL Full, and between RDFS and OWL, seem to me to cause a lot  
of confusion in new users - I meet way too many people who think they  
"have to" use one thing or another, often for a wrong reason, and  
anywhere there is confusion in these things it means we increase a  
learning curve and lose some potential users
  -JH
p.s. I should be clear I am not actually making a technical point  
here, I'm just bemoaning a state of the world.


On Dec 11, 2007, at 8:58 AM, Michael Schneider wrote:

> Hi, Jim!
>
> Jim Hendler wrote:
>
>> So basically, we have two different groups who end up coming
>> at things from different directions and not meeting in the
>> middle.  I'd love to see a fix, but I also understand the
>> worldview that cannot live with this.
>> but I'll tell you this based on experience and analysis of
>> lots of stuff out there - telling people that the "right
>> thing" to do is to use owl:class won't change much, because
>> the people using rdfs:class to start with generally aren't
>> coming from an OWL perspective, and therefore don't see a
>> reason to change.
>>  So I see that if there was a solution in resolving these, we
>> would make it easier for people to come to OWL
>
> But please note that my "second recommendation" just targeted on  
> this. While
> in my "first recommendation" I suggested to use "owl:Class" in all / 
> new/ OWL
> ontologies, I also suggested that the OWL reasoner developers  
> should change
> their reasoners to silently substitute occurrences of "rdfs:Class" by
> "owl:Class" before reasoning starts. Technically this is very  
> simple: Just
> look up all triples containing "rdfs:Class" and substitute them by  
> the same
> triples containing "owl:Class" instead. This is a matter of a few  
> lines of
> code with JENA, for example.
>
> Cheers,
> Michael
>
> --
> Dipl.-Inform. Michael Schneider
> FZI Forschungszentrum Informatik Karlsruhe
> Abtl. Information Process Engineering (IPE)
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"If we knew what we were doing, it wouldn't be called research, would  
it?." - Albert Einstein

Prof James Hendler				http://www.cs.rpi.edu/~hendler
Tetherless World Constellation Chair
Computer Science Dept
Rensselaer Polytechnic Institute, Troy NY 12180