Re: Fragments discussion, continued

 I can not call in today but have a couple of comments for the fragment conversation.
I strongly support the position that we should
(a) have at least one fragment that supports a target community (that has some explicit description).
(b) not have too many official fragments

I (and collaborators of mine) would find value in all 3 of the suggestions below from alan.

i agree with alan's suggestion below on owl lite that we "keep" it and have a document about it.
one question is what kinds of things are we going to do for the "official" new fragments and how does that compare to what we are going to do for OWL lite?

thanks,
deborah







It seems (I hope) we are getting closer to some sort of mutual understanding of our needs for fragments. I'd like to sketch out the shape of what I'd be happy to see as an outcome of tomorrow's meeting.?
?

I think we've heard convincing arguments that having a large number of fragments in Rec track, absent strong justification for each, isn't desirable. On the other hand, I'd like to put forward that there are compelling reasons to acknowledge OWL Lite, in the manner I've proposed, and to put 3 fragments on rec track, and proceed in subsequent meetings to nail down details of specification and documentation.?
?

The fragments:?
?

1) OWL Prime (details of exactly what is in or out of OWL Prime remain to be worked out). Justified by specific industry interest from Oracle and HP, and to address the constituency that wishes to have a workable and more easily understandable rule-based OWL.?

2) EL++. Justified by existing academic and commercial implementations, useful computational properties (polytime) and demonstrated use for working with important ontologies for biomedicine, a field which has been at the leading edge of Semantic Web adoption.?

3) A fragment characterized by scalability to large numbers of instances (not necessarily scalable tbox) , but with strong guarantees with respect to completeness and consistency detection.?

This is probably DL-Lite, but I want to leave the door open to input from IBM, who's SHER implementation might also fit the bill. We haven't discussed this fragment much, so I'll give my view of why it is justified. Such a fragment  fills a hole that neither of two other fragments fill, as It is likely that OWL Prime will not allow existentials in  a rule head (following pD*), and EL++ is not as scalable. In addition DL-Lite is implementable in relational databases with queries translatable to SQL. I have heard of two academic implementations ("the italians" &  Jeff Pan) and a commercial implementation - Clark and Parsia's, and the nature of the fragment is such that it would be easily adoptable by relational database providers. Finally, it is my judgement, as a user, that strong guarantees of the ability to detect inconsistency and give complete answers bring high value to science applications.?
?

To recap the OWL Lite proposal, the suggestion is to keep OWL Lite, unchanged, to support existing users, verify that it behaves as before using OWL 1.1 DL semantics, and write a Note to explain its status.?
?

Remaining fragments in the current Fragments document, would be described in one or more WG Notes.?
?

My hope would be to not necessarily work out all the details tomorrow, but instead to come to agreement on this number of fragments (3) and their character, so that subsequent meetings  can be focused on implementation rather than policy.?
?

Regards,?

Alan?
?

?

 


 


 

-----Original Message-----
From: Alan Ruttenberg <alanruttenberg@gmail.com>
To: Web Ontology Language ((OWL)) Working Group WG <public-owl-wg@w3.org>
Sent: Tue, 19 Feb 2008 10:27 am
Subject: Fragments discussion, continued










It seems (I hope) we are getting closer to some sort of mutual understanding of our needs for fragments. I'd like to sketch out the shape of what I'd be happy to see as an outcome of tomorrow's meeting.?
?

I think we've heard convincing arguments that having a large number of fragments in Rec track, absent strong justification for each, isn't desirable. On the other hand, I'd like to put forward that there are compelling reasons to acknowledge OWL Lite, in the manner I've proposed, and to put 3 fragments on rec track, and proceed in subsequent meetings to nail down details of specification and documentation.?
?

The fragments:?
?

1) OWL Prime (details of exactly what is in or out of OWL Prime remain to be worked out). Justified by specific industry interest from Oracle and HP, and to address the constituency that wishes to have a workable and more easily understandable rule-based OWL.?

2) EL++. Justified by existing academic and commercial implementations, useful computational properties (polytime) and demonstrated use for working with important ontologies for biomedicine, a field which has been at the leading edge of Semantic Web adoption.?

3) A fragment characterized by scalability to large numbers of instances (not necessarily scalable tbox) , but with strong guarantees with respect to completeness and consistency detection.?

This is probably DL-Lite, but I want to leave the door open to input from IBM, who's SHER implementation might also fit the bill. We haven't discussed this fragment much, so I'll give my view of why it is justified. Such a fragment  fills a hole that neither of two other fragments fill, as It is likely that OWL Prime will not allow existentials in  a rule head (following pD*), and EL++ is not as scalable. In addition DL-Lite is implementable in relational databases with queries translatable to SQL. I have heard of two academic implementations ("the italians" &  Jeff Pan) and a commercial implementation - Clark and Parsia's, and the nature of the fragment is such that it would be easily adoptable by relational database providers. Finally, it is my judgement, as a user, that strong guarantees of the ability to detect inconsistency and give complete answers bring high value to science applications.?
?

To recap the OWL Lite proposal, the suggestion is to keep OWL Lite, unchanged, to support existing users, verify that it behaves as before using OWL 1.1 DL semantics, and write a Note to explain its status.?
?

Remaining fragments in the current Fragments document, would be described in one or more WG Notes.?
?

My hope would be to not necessarily work out all the details tomorrow, but instead to come to agreement on this number of fragments (3) and their character, so that subsequent meetings  can be focused on implementation rather than policy.?
?

Regards,?

Alan?
?

?




 


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