- From: Jim Hendler <hendler@cs.rpi.edu>
- Date: Mon, 25 Aug 2008 10:59:15 -0400
- To: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
- Cc: Ivan Herman <ivan@w3.org>, public-owl-wg Group WG <public-owl-wg@w3.org>
+1 to dropping the "2" from the profiles. -JH On Aug 25, 2008, at 10:34 AM, Ian Horrocks wrote: > > On 25 Aug 2008, at 14:12, Ivan Herman wrote: > >> Hi Ian, >> >> first of all: thank you! >> >> I have some editorial issues/questions/comments on the profile >> document. >> I may also have some more content questions at some point, but I >> thought >> it would be better to get the editorial comments out of the way... So >> here they are. >> >> - In the definition of OWL 2 EL, you refer to "satisfiability, >> subsumption, classification, and instance checking" as being >> polynomial. >> On the other hand, the introduction refers to "consistency, >> classification, instance checking, and conjunctive query" as the >> reasoning tasks used to describe the profiles. I think that the >> introduction should describe all of those. Having said that: aren't >> 'satisfiability' and 'consistency' the same, or am I missing the >> point? > > This clearly needs tidying up a bit and making more consistent > across the profiles. Consistency and satisfiability are often used > interchangably. I might be able to persuade myself that the > unqualified use of consistency usually refers to ontology > consistency (is there any model of the ontology as a whole) whereas > the unqualified use of satisfiability usually refers to classes (is > there a model of the ontology in which the interpretation of a given > class is non-empty). However, I think that it is better to > explicitly distinguish when we are talking about the ontology and > when we are talking about classes (e.g., ontology/class consistency). > >> >> - In EL, bulleted item under 'The following features...', 2nd item, >> there seem to be an extra ')' in the middle and an extra one at the >> end, too > > Fixed. > >> >> - Section 3, introduction on QL, second paragraph refers to DL-Lite >> and >> not QL, which is a bit out of the blue here (I suspect this is a >> leftover). Actually, I wonder whether that paragraph should stay at >> all. > > I changed it to say that QL is based on a variant of DL-Lite. I > think this is useful as it allows us to explain the basis for QL, to > point to the literature and explain why this particular variant was > chosen. > >> >> - Whereas the start up section of EL referred to the various >> reasoning >> problems for which EL is well suited for, this is not so explicitly >> stated for QL. I think it would be good to have a similar >> characterization of QL, too; if _all_ reasoning problems are in >> LOGSPACE, then it should be said explicitly. > > Good point. Some more work is needed on the introductory and > explanatory text throughout the document. It has lagged a bit behind > the others due to the "planning blight" caused by the possible > unification. Once this is resolved one way or the other we can get > on with this work. > >> >> - Section 4, introducing OWL RL, I actually have the same comment as >> before: it may be useful to be able to characterize (at least >> partially) >> the profile with the reasoning problems. For example, isn't it >> correct >> that the OWL 2 RL/RDF rules are not complete vs. classification but >> they >> are vs. conjuctive query and instance checking, for example? > > I agree that we should be clearer about all this. Completeness > depends mainly on the structure of the ontology. If the ontology > satisfies the relevant syntactic conditions, then the rules are > complete for ground entailment. This means that they can also be > used for complete consistency checking (both class and ontology), > subsumption and classification. E.g., C is a subClassOf D just in > case asserting T(a rdf:type C) entails T(a rdf:type D) for some "a" > that is not mentioned elsewhere in the ontology. This is a standard > technique in rule based reasoning. > > >> >> (I think the reference to these reasoning tasks is a very good way of >> comparing the various profiles, hence these remarks...) >> >> - I do not want to reopen the profile naming discussion too much, >> but:-( >> Is it necessary to add the '2' to all profiles? I would have thought >> that 'OWL QL', 'OWL RL', etc, would be o.k. It would also make the >> rule >> representation a bit shorter: 'OWL RL/RDF' instead of 'OWL 2 RL/RDF' > > This would be fine for me -- there is no confusion because OWL 1 > didn't have these profiles. If others agree, then changing the > document is a trivial task. > > Ian > > >> >> I guess that is for the moment after a first read through the text... >> >> Thanks >> >> Ivan >> >> Ian Horrocks wrote: >>> >>> We (Alan and I) agreed that it would help to clarify this issue >>> and to >>> inform our discussion on Wednesday if the Profiles document [1] were >>> updated to reflect the proposed "unification". This has now been >>> done. >>> It should be read in conjunction with the (draft) conformance >>> definitions [2]. >>> >>> Regards, >>> Ian >>> >>> [1] http://www.w3.org/2007/OWL/wiki/Profiles >>> [2] http://www.w3.org/2007/OWL/wiki/Conformance >>> >> >> -- >> >> Ivan Herman, W3C Semantic Web Activity Lead >> Home: http://www.w3.org/People/Ivan/ >> PGP Key: http://www.ivan-herman.net/pgpkey.html >> FOAF: http://www.ivan-herman.net/foaf.rdf > > "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
Received on Monday, 25 August 2008 14:59:54 UTC