- From: Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>
- Date: Tue, 7 Apr 2009 16:40:04 +0100
- To: Christine Golbreich <cgolbrei@gmail.com>
- Cc: Sandro Hawke <sandro@w3.org>, W3C OWL Working Group <public-owl-wg@w3.org>, Peter Patel-Schneider <pfps@research.bell-labs.com>
Thanks for that. I have updated the section in NF&R and added a suitable pointer to the Overview. IMHO this is all now in pretty good shape. Ian On 6 Apr 2009, at 23:22, Christine Golbreich wrote: > I rapidly drafted something from bits of your texts (sorry but did not > yet included Sandro's comments: have to recover it in the stack of > emails) > > Here a possible a pointer: > http://www.w3.org/2007/OWL/wiki/ > New_Features_and_Rationale#Backward_Compatibility > > Any improvements or fixesr are welcome > > Christine > > 2009/4/6 Ian Horrocks <ian.horrocks@comlab.ox.ac.uk>: >> As per your suggestion I removed the one sentence explanation of >> the meaning >> of "to all intents and purposes", replacing it with a pointer to >> NF&R. This >> will need to be fixed to a more precise reference to the location >> of the >> relevant section when it has been added. >> >> I heard different opinions about Figure 2, so I didn't do anything >> on that >> pending a decision from the WG. It seems slightly ridiculous for >> such a >> minor issue, but I suggest that we put it on this weeks agenda for >> discussion and disposition vote on it. >> >> Ian >> >> >> On 3 Apr 2009, at 20:02, Sandro Hawke wrote: >> >>> >>>>>>> 2.4/ Profiles: >>>> >>>>>>> Remove Figure 2, as it serves no useful purpose. >>>> >>>> I'm baffled as to what purpose you think this figure serves and why >>>> its loss will be mourned. AFAICT, the information content of the >>>> figure is: >>>> ... >>> >>> It's not intended to provide additional information; it's about >>> presentation. It's intended to make the relationship between the >>> profiles feel as simple as it actually is. A simple-looking diagram >>> conveys that feeling much more effectively, I think, than the text. >>> >>> But perhaps that's just me, so I'm okay with letting it go until/ >>> unless >>> others speak up for it. >>> >>>>>>> Could remove the subsection headers, as the subsections are >>>>>>> all very >>>>>>> short. >>>>>>> >>>>>>> >>>>>>> Change "albeit under a possibly different name." to >>>>>>> "albeit possibly under different names." >>>>>>> >>>>>>> Remove "; it also has a formal equivalence to UML [UML]." >>>>>>> This is just *wrong*. >>>>>>> >>>>>>> 3.2: >>>>>>> Just put this stuff elsewhere (perhaps in Primer). >>>>>> >>>>>> I significantly shortened the whole of Section 3 and pointed >>>>>> to NF&R >>>>>> for detailed explanation/documentation. >>>>>> >>>>>> I also renamed it "Relationship to OWL 1" as this seems more >>>>>> appropriate and avoids the negative connotations of >>>>>> "differences". >>>>> >>>>> Very nice, except that we need a link explaining the "almost"s in >>>>> paragraph two to a place with text like Peter and I were crafting >>>>> yesterday. If I were an OWL 2 user, I would insist the text >>>>> actually be >>>>> normative, too. (I guess there's no problem with a little >>>>> normative >>>>> text in NF&R.) >>>>> >>>>> Am I the only one who thinks OWL 1 users will want to know, in no >>>>> uncertain terms, whether OWL 2 breaks their stuff, BEFORE they >>>>> accept >>>>> OWL 2? >>>> >>>> This is *exactly* what I am trying to achieve here. >>>> >>>>> Figuring that out by sifting through our entire spec seems a bit >>>>> much to ask. >>>> >>>> That isn't the intention. The intention is to tell them that >>>> everything is fine, *which it is*. IMHO this message, we should >>>> *not* >>>> provide irrelevant information about the corner cases and "bug- >>>> fixes" >>>> in OWL 2 that prevent us from simply saying that it is *completely* >>>> backwards compatible with OWL 1 -- this does need to be documented >>>> somewhere, but not here (not sure if it should be normative and/ >>>> or in >>>> NF&R, but this is a different issue that I will address in another >>>> email). >>>> >>>> I changed what is said here to make the message even more clear: it >>>> now says that "backwards compatibility with OWL 1 is, to all >>>> intents >>>> and purposes, complete" and that inferences are identical "in all >>>> practical cases". I also added a note explaining that "even the >>>> theoretical possibility of different entailments arises only from a >>>> change in the treatment of annotations in the Direct Semantics >>>> [OWL 2 >>>> Direct Semantics] that reflects what was typically implemented >>>> in OWL >>>> 1 systems". I'm ambivalent about this note -- we could simply say >>>> "see XXX for more details". >>> >>> Okay, yeah, I think this works. I'd leave off the note and put a >>> link >>> to the appropriate non-normative section of NF&R, so if people >>> want to >>> double check whether they agree with our notion of "all intents and >>> purposes" and "impractical", they easily can. >>> >>>> BTW, given that the differences in entailments only affect OWL >>>> DL and >>>> derive from changes in the Direct Semantics, it seems to me that >>>> this >>>> is the right place to document them. >>> >>> I'd lean towards having the change descriptions grouped together, >>> for >>> those people who care about the changes. In the future, hopefully, >>> folks reading the OWL 2 DL specs wont care how it differed from >>> OWL 1 >>> DL. >>> >>> -- Sandro >> >> >> > > > > -- > Christine
Received on Tuesday, 7 April 2009 15:40:48 UTC