- From: Dimitris Kontokostas <kontokostas@informatik.uni-leipzig.de>
- Date: Thu, 27 Nov 2014 07:48:27 +0200
- To: "Peter F. Patel-Schneider" <pfpschneider@gmail.com>
- Cc: Holger Knublauch <holger@topquadrant.com>, "public-data-shapes-wg@w3.org" <public-data-shapes-wg@w3.org>
- Message-ID: <CA+u4+a2iesOmi04ZAYcaf=SwQ3PLp+WR0zpt1ERuc+UOT+KGgw@mail.gmail.com>
On Thu, Nov 27, 2014 at 2:32 AM, Peter F. Patel-Schneider < pfpschneider@gmail.com> wrote: > I think that the relevance of this part of the thread is whether > associating constraints/shapes with ontologies commits one to using those > shapes. The argument against committing appears to be that one would then > lose interoperability. > I think 'committing' is too strong. IMHO this should be an option (perhaps the default) but it should be easy to override this. I wrote about this and how RDFUnit deals with it in the public-shapes list http://lists.w3.org/Archives/Public/public-rdf-shapes/2014Jul/0019.html http://lists.w3.org/Archives/Public/public-rdf-shapes/2014Aug/0104.html Here's details on how we have it as the default option but easily overridable by the user on runtime http://lists.w3.org/Archives/Public/public-data-shapes-wg/2014Nov/0245.html Best, DImitris > > I very much agree that both SPIN and OWL constraints have very flexible > mechanisms for associating constraints with particular nodes in an RDF > graph. It is not the case that the only constraints that you can use in > these schemes are those that belong to an ontology. > > I also very much agree that in many cases information will be produced and > consumed inside a particular entity (such as a company) where strict > control is possible. > > peter > > > > On 11/26/2014 03:02 PM, Holger Knublauch wrote: > >> I am puzzled about the purpose of this topic here. What are we trying to >> achieve? >> >> There are tons of statements that I disagree with here in this thread. In >> particular we should not cloud our design of a new language by situations >> that >> were created with open world/reasoning languages like OWL and RDF Schema. >> The >> fact that those languages have been there first does not mean that they >> are >> the only interpretation of semantic web technology. Property reuse across >> ontologies was often driven by data merging use cases (via rdfs:domain >> inferencing). If you take RDFS/OWL inferencing out (which we hopefully >> do), >> then the desire to reuse properties is much less relevant. >> >> In the end, the shapes language should allow designers to chose how they >> publish their constraints, and there are already plenty of techniques to >> either work around global definitions (e.g. redefining terms), or separate >> constraints from class/property definitions into different named graphs. >> So I >> am not sure what this discussion is about here, and how it would >> influence our >> technology choices. >> >> I also want to highlight that we are not just talking about "the Semantic >> Web" >> as a whole. I believe most successful applications of this technology are >> actually inside of closed company networks, where strict semantic >> contracts >> can and have to be enforced. >> >> Holger >> >> >> On 11/27/2014 8:36, Eric Prud'hommeaux wrote: >> >>> * Peter F. Patel-Schneider <pfpschneider@gmail.com> [2014-11-26 >>> 07:20-0800] >>> >>>> On 11/26/2014 05:46 AM, Eric Prud'hommeaux wrote: >>>> >>>>> * Peter F. Patel-Schneider <pfpschneider@gmail.com> [2014-11-26 >>>>> 05:11-0800] >>>>> >>>>>> One usually uses an external URI, like foaf:mbox, because one wants >>>>>> interoperability of meaning. However, I do not believe that >>>>>> complete interoperability of URI meaning should be mandated. I also >>>>>> do not believe that complete interoperability of URI meaning is >>>>>> possible. >>>>>> >>>>>> Further, I believe that effective interoperability can be achieved >>>>>> without mandating use of defining definitions. For example, I may >>>>>> decide that I don't want to use the "static" part of the definition >>>>>> of foaf:mbox. Interoperability should remain for most purposes. >>>>>> >>>>>> Particular commmunities can, if they want, require stronger >>>>>> conditions on shared meaning. Perhaps it would be possible to set >>>>>> up a community that achieves complete interoperability of meaning. >>>>>> However, I very strongly believe that "the web" cannot be such a >>>>>> community, and thus that W3C recommendations should never mandate >>>>>> it. >>>>>> >>>>> It sounds like if I'm not feeling lucky, I should never consume data >>>>> >>>> >from anyone with whom I've not written up some contract. What would >>>> >>>>> that contract say? "I agree to use the vocabularies according to their >>>>> documented semantics. I will not use terms if I don't understand their >>>>> semantics." >>>>> >>>> I don't think that you have to have a direct contract with that >>>> other party. There could be some out-of-band information about that >>>> other party, for example that they are a participant in some >>>> community. There could also be information in documents, such as >>>> the use of logical properties, like rdf:type or owl:imports. Sure a >>>> particularly perverse player could use these properties differently >>>> than you expect, either intentionally or inadvertently, but using >>>> logical properties in a non-standard fashion is something that >>>> should only be done, in my view, with great trepidation. >>>> >>>> (Of course, I'm actually going against web practice here somewhat. >>>> There are many situations where logical properties are not used >>>> correctly. Consider owl:sameAs, for example.) >>>> >>>> Merging data from different sources can be problematic even if the >>>>>> use of defining definitions is mandated. Data can be incorrect, >>>>>> after all. >>>>>> >>>>> I suspect you are being a bit provocative here, >>>>> >>>> Not at all, I've held this position from the very beginning of my >>>> involvement with the semantic web. I and others have forcefully >>>> argued it at various meetings, and have affected W3C recommendations >>>> thereby. >>>> >>>> and I'm playing along >>>>> nicely. Surely we needn't jettison this fine bathwater just because >>>>> it's slightly sullied by a baby. It's quite practical to say that I >>>>> will respect, or at least not contradict, the properties of foaf:mbox >>>>> even if there's an assertion elsewhere in that ontology that the moon >>>>> is a subclass of Things made of green cheese. What's the actual >>>>> screw-case if I use <http://dbpedia.org/resource/Moon>? >>>>> >>>> Well, you do commit to lots of unusual things in this case. For >>>> starters, there are several minimum and maximum temperatures. >>>> >>>> If you commit to the DBpedia ontology you get a number of unusual >>>> consequences, like Berlin being a mountain and Lambeau Field being a >>>> city. You also commit to unusual definitions of many categories. >>>> For example, all windmills are buildings, all libraries are >>>> educational institutions, chess players are athletes, saints are >>>> clerics, baronets are british royalty, professors are scientists. >>>> >>> OK, let's take a fairly pessimal case and utter >>> dbp:Deep_Blue :wonAgainst dbp:Garry_Kasparov . >>> and this peculiarly entails that Deep Blue is a dbp:Athlete. >>> dbp:Deep_Blue a dbp:Athlete . >>> >>> No one will have any problems consuming our little assertion unless >>> their logic somehow interacts with the wikipedia hierarchy, in which >>> case they're already marrying an ontology with known bugs. >>> >>> >>> I care about this sort of thing because I want to use the >>>> consequences of web information in my systems. I don't want to have >>>> to commit to too much, however. I also want to be able to commit to >>>> some things and see when the sources that I do use have committed to >>>> other things. I certainly don't want to have to commit to the >>>> entire web to use any of it. >>>> >>>> peter >>>> >>> >> >> > -- Dimitris Kontokostas Department of Computer Science, University of Leipzig Research Group: http://aksw.org Homepage:http://aksw.org/DimitrisKontokostas
Received on Thursday, 27 November 2014 05:49:23 UTC