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Re: Review of Primer

From: Sebastian Rudolph <rudolph@aifb.uni-karlsruhe.de>
Date: Wed, 20 May 2009 12:12:16 +0200
Cc: "W3C OWL Working Group" <public-owl-wg@w3.org>
Message-Id: <86D61C79-46A6-4CEF-B774-628F7873CEA2@aifb.uni-karlsruhe.de>
To: Michel_Dumontier <Michel_Dumontier@carleton.ca>
Dear Michel,

Am 19.05.2009 um 20:57 schrieb Michel_Dumontier:

> Hi Sebastian/Pascal,
>   I still think that the HappyPerson example is still not ideal  
> because of the cyclic definition. Its easier to understand if you  
> just say that
> EquivalentClasses(
>  :HappyPerson
>  ObjectAllValuesFrom( :hasChild :Person)
> )

We understand your concern, yet the variant you suggest is problematic  
as it would classify *all* entities as HappyPersons that don't happen  
to have non-Persons as children (such as possibly animals). I think  
this may even more confusing than the current one. We have discussed  
possible alternatives but were not really satisfied by any of them,  
except for the current one.

> While I understand that you want to make the point that we can  
> express cycles, it adds a layer of complexity that is unnecessary  
> and its utility in this example is not particularly convincing.

Triggered by that comment, I asked some colleagues and they found the  
statement "somebody is a happy Person iff all his/her children are  
happy Persons" quite natural.
For those reasons we would really prefer to leave the example as it  
is. But I added a sentence after the example explicitly hinting at the  
self-referentiality of this statement and that this is OK.

> Grammar:
> If we happen to know the exact number of John's parent children,  
> this can be specified as follows:
>  If we happen to know the exact number of John's children that are  
> parents, this can be specified as follows:

Thanks a lot for this hint, we corrected that.

Best regards,

> I cant validate either the RDF/XML or Functional Syntax of the  
> supplied ontology  what tools I can I use to do this?
> -=Michel=-
> From: Sebastian Rudolph [mailto:rudolph@aifb.uni-karlsruhe.de]
> Sent: Saturday, May 16, 2009 12:41 PM
> To: Michel_Dumontier
> Cc: W3C OWL Working Group
> Subject: Re: Review of Primer
> Dear Michel,
> thanks a lot for your review. We have thoroughly considered all your  
> comments and tried to address them.
> Please bear with us for not having implemented all your replacement  
> text suggestions word by word, however we tried to detect your  
> concerns behind those suggestions and to adress them apropriately.
> Diff of Sections 1-8 addressing your suggestions:
> http://www.w3.org/2007/OWL/wiki/index.php?title=Primer&diff=23574&oldid=23545
> Diff for Section 10: <http://www.w3.org/2007/OWL/wiki/index.php?title=Primer&diff=23695&oldid=23689 
> >
> With best regards,
>  Sebastian
> Find some specific comments below.
> Review of the OWL 2 Primer (WD 21/04/09)
> ---------------------------------------
> 1.
> * "the buttons below can be used to show or hide all four syntaxes" ->
> five syntaxes
> * the syntax buttons aren't immediately linked to syntax examples,  
> so a
> user wouldn't understand the differences between them and wouldn't
> choose between any of them at this point. On first exposure (4 -
> classes, instances), unclear which syntax each box refers to, but the
> user would have to scroll up to hide the syntax, go check which was
> changed, etc.
> Meanwhile, the boxes have been endowed with labels indicating the  
> syntax.
> *** the Happy example is really obfuscated -> we should stay with  
> named
> classes and build on previous defs
> Yes, it may be confusing to have a complex class description on the  
> left hand side, so we adapted the example. However, in OWL,  
> "circular" statements (or in DL-parlance: cyclic Tboxes) are allowed  
> and extend the modelling capabilities. In our example, we wanted to  
> provide an example for this (hence describing "HappyPerson" using   
> "HappyPerson"). Thus we deliberately deviated from building on  
> previous defs.
> Section 10:
> * Remove most of the current text - it's really not accessible because
> it introduces huge amounts of new and unexplained terminology that is
> unrelated to what precedes it
> We have done this.
> * I think there would be more value in treating OWL 2 DL, Full, EL, RL
> and QL all as profiles of the OWL language.
> We actually had considered this when we started working on the  
> primer but decided against it. We think the exhibition is much more  
> concise as it is now, and fits the OWL 2 document set (where OWL 2  
> DL is not explicitly introduced as a profile).
> * A table that compares the profile features, and the additional
> interpretation for FULL
> To be entirely honest, I (Pascal) would very much like to come up  
> with a readable table which presents the differences in a nice and  
> accessible way. But the more I think about it, the less I like it.  
> The profiles are simply too orthogonal. I'd be very happy about a  
> concrete suggestion what such a table would look like - and if it is  
> satisfactory, I'd be very happy to incorporate this.
> * Use one example to illustrate the support for/differences between  
> the
> profiles with an axiom annotation - and make the idea of profiles more
> accessible. Either start with a weaker profile and successively add  
> more
> constructs, or summarizes the support in one example.
> This is a nice idea but since the profiles EL, QL, RL are not  
> layered, I think this way of presenting it is more confusing than  
> helpful. It would either turn out to be mainly a merge of three  
> disjoint sets of axioms, or it would be an example which is  
> unneccessarily blown up (by forcing axioms into the example which  
> lie in two or all three of the profiles). The exhibition seems to be  
> much clearer as it is - and it also brings the point accross that  
> the profiles should be thought of as orthogonal to each other.
> * comparisons with RDFS precedes its  description
> I do not quite understand this comment?
> Diff for Section 10: <http://www.w3.org/2007/OWL/wiki/index.php?title=Primer&diff=23695&oldid=23689 
> >
> _________________________________________________
> Dr. Sebastian Rudolph
> Institute AIFB, University of Karlsruhe, D-76128 Karlsruhe
> rudolph@aifb.uni-karlsruhe.de    phone +49 (0)721 608 7362
> www.sebastian-rudolph.de                 fax +49 (0)721 608 5998

Dr. Sebastian Rudolph
Institute AIFB, University of Karlsruhe, D-76128 Karlsruhe
rudolph@aifb.uni-karlsruhe.de    phone +49 (0)721 608 7362
www.sebastian-rudolph.de                 fax +49 (0)721 608 5998
Received on Wednesday, 20 May 2009 10:13:47 UTC

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