Re: ontology mapping etiquette (was What is the class of a Named Graph?)
On Feb 23, 2010, at 10:47 AM, Jiří Procházka wrote: On 02/22/2010 09:44 PM, Richard Cyganiak wrote: On 22 Feb 2010, at 19:36, Jiří Procházka wrote: I wonder if we as a group of people interested in Semantic Web could come up with etiquette for ontology mapping. Interesting topic! My €0.02: If the other vocabulary is likely to be - more stable - more mature - more likely to be widely used - more likely to be around for a longer time then you should map your terms to it. If not, don't. So IMO the rdfg vocabulary should map to the SPARQL Service Description vocabulary as soon as it becomes REC, but SPARQL-SD should NOT map to rdfg. Hi Richard, that also seems reasonable to me at first, but when thinking about it more thoroughly, there is value in both ontologies doing the mapping to the other. Yes, if both sides agree, then two-way mappings are great. But this is only realistic if both vocabularies rate about equally on the criteria above. As an extreme example, it would be totally unrealistic to expect the RDFS vocabulary to link back to every vocabulary that has some sort of label/name property (all of which should be subproperties of rdfs:label). Yes, I had in mind especially equivalentClass/Property relations and alike where it doesn't scale much, not subproperties. Certain mapping statements make sense from PoV of one ontology, but not the other. I don't know what you mean. An example might help. But anyway, if you map to my ontology, but from my POV that mapping doesn't make sense, then I'm certainly not going to map back to yours. I mean when the philosophies of the creators of the ontologies aren't mutually compatible. I'm unable to come up with some example but just let's say that someday we will have religious ontologies... No need to wait. Already we have for example ontologies which list all the elements in the periodic table, others which distinguish isotopes. C12 and C14 are both Carbon seen from the non-isotope end, but have to be distinguished at the radioactive end. Another example, Cyc (and Umbel based on it) say that an element like sodium is a *class* whose elements are all *mereological sums* of pure sodium. Dbpedia mentions sodium, and they have links, but I bet that most users of Dbpedia wouldn't buy into the Cyc ontological craftiness. Pat Hayes If we allow ourselves to go a bit further, I thought it would be great if there was some community developed service which would in automated fashion give advice for improvement and rate user submitted (better yet WoD collected) ontologies judging their quality of design - most importantly re-usability which basically means how is it aligned to other similar ontologies. This would be probably very difficult, at least because of varying opinions on this... I guess database community has something to say about that. I think that's a different issue. When it comes to rating the “quality” of a vocabulary, then the amount of mappings to other vocabularies is a very minor factor. First, because other things (especially amount of uptake and strength of the surrounding community) are much more important. Second, because adding the mappings is so easy. No vocabulary will succeed or fail because of its inclusion or lack of mappings. Strength of community and amount of uptake matters really a lot, but next thing you are interested in is how an ontology is compatible with the rest of your knowledge - how good the mappings are and if it has mappings to its "competitors", because the they can have mappings to other ontologies you have not (and how they are good). Nevertheless, I agree that we need services that support us in finding high-quality vocabularies, and that help drive the improvement of existing ones. But it's a complex subject, there are many existing efforts (Watson, Talis Schema Cache, Falcons Concept Search, ontologydesignpatterns.org, and I probably missed a few), and to me it's not obvious what is the right approach. Perhaps we don't need better ways of finding and creating vocabularies, but better ways of finding and creating communities around a domain that can then jointly agree on a vocabulary. Great point! I would love to see some development in this area... All the best, Richard There are more things to talk about regarding this, but this is what I have in mind so far. Best, Jiri Best, Richard Best, Jiri Hope that helps. thanks, .greg [1] http://www.w3.org/TR/sparql11-service-description/#id41794 IHMC (850)434 8903 or (650)494 3973 40 South Alcaniz St. (850)202 4416 office Pensacola(850)202 4440 fax FL 32502 (850)291 0667 mobile phayesAT-SIGNihmc.us http://www.ihmc.us/users/phayes
Re: What is the class of a Named Graph?
On Feb 22, 2010, at 5:51 AM, Jiří Procházka wrote: > On 02/22/2010 05:54 AM, Gregory Williams wrote: > >> The next draft of the service description document will likely include a >> named graph class to go along with the property mentioned above. If the >> modeling in the example section[1] works for the named graphs you're hoping >> to describe (the named graph pointed to by the sd:namedGraph property), then >> the new class will probably be what you're after. > > I wonder if it would owl:equivalentClass the rdfg:Graph. > Ontology mapping is important or the main advantage of RDF over XML and > such is lost. I guess no W3C standard did that yet. I believe it would be hard to have the SD document reference an ontology that isn't a standard. This is already the reason it's difficult to talk about serializing quads in things like SPARQL as I don't believe any of the formats are properly standardized (TriG, TriX, N-Quads). I'd be happy to see linking happen *to* the SD terms, but I'm doubtful that the SD document could link to external terms. That being said, if you'd like to make an official comment on this topic, please do send a message to public-rdf-dawg-comme...@w3.org, and the working group will address it formally. thanks, .greg
Re: ontology mapping etiquette (was What is the class of a Named Graph?)
On 02/22/2010 09:44 PM, Richard Cyganiak wrote: > On 22 Feb 2010, at 19:36, Jiří Procházka wrote: I wonder if we as a group of people interested in Semantic Web could come up with etiquette for ontology mapping. >>> >>> Interesting topic! My €0.02: If the other vocabulary is likely to be >>> >>> - more stable >>> - more mature >>> - more likely to be widely used >>> - more likely to be around for a longer time >>> >>> then you should map your terms to it. If not, don't. >>> >>> So IMO the rdfg vocabulary should map to the SPARQL Service Description >>> vocabulary as soon as it becomes REC, but SPARQL-SD should NOT map to >>> rdfg. >> >> Hi Richard, that also seems reasonable to me at first, but when thinking >> about it more thoroughly, there is value in both ontologies doing the >> mapping to the other. > > Yes, if both sides agree, then two-way mappings are great. But this is > only realistic if both vocabularies rate about equally on the criteria > above. As an extreme example, it would be totally unrealistic to expect > the RDFS vocabulary to link back to every vocabulary that has some sort > of label/name property (all of which should be subproperties of > rdfs:label). Yes, I had in mind especially equivalentClass/Property relations and alike where it doesn't scale much, not subproperties. > >> Certain mapping statements make sense from PoV of one ontology, but not >> the other. > > I don't know what you mean. An example might help. But anyway, if you > map to my ontology, but from my POV that mapping doesn't make sense, > then I'm certainly not going to map back to yours. I mean when the philosophies of the creators of the ontologies aren't mutually compatible. I'm unable to come up with some example but just let's say that someday we will have religious ontologies... > >> If we allow ourselves to go a bit further, I thought it would be great >> if there was some community developed service which would in automated >> fashion give advice for improvement and rate user submitted (better yet >> WoD collected) ontologies judging their quality of design - most >> importantly re-usability which basically means how is it aligned to >> other similar ontologies. This would be probably very difficult, at >> least because of varying opinions on this... I guess database community >> has something to say about that. > > I think that's a different issue. When it comes to rating the “quality” > of a vocabulary, then the amount of mappings to other vocabularies is a > very minor factor. First, because other things (especially amount of > uptake and strength of the surrounding community) are much more > important. Second, because adding the mappings is so easy. No vocabulary > will succeed or fail because of its inclusion or lack of mappings. Strength of community and amount of uptake matters really a lot, but next thing you are interested in is how an ontology is compatible with the rest of your knowledge - how good the mappings are and if it has mappings to its "competitors", because the they can have mappings to other ontologies you have not (and how they are good). > Nevertheless, I agree that we need services that support us in finding > high-quality vocabularies, and that help drive the improvement of > existing ones. But it's a complex subject, there are many existing > efforts (Watson, Talis Schema Cache, Falcons Concept Search, > ontologydesignpatterns.org, and I probably missed a few), and to me it's > not obvious what is the right approach. > > Perhaps we don't need better ways of finding and creating vocabularies, > but better ways of finding and creating communities around a domain that > can then jointly agree on a vocabulary. Great point! I would love to see some development in this area... > All the best, > Richard > > >> >> There are more things to talk about regarding this, but this is what I >> have in mind so far. >> >> Best, >> Jiri >> >>> Best, >>> Richard >>> >>> Best, Jiri > > Hope that helps. > > thanks, > .greg > > > [1] http://www.w3.org/TR/sparql11-service-description/#id41794 > >>> >> > signature.asc Description: OpenPGP digital signature
Re: ontology mapping etiquette (was What is the class of a Named Graph?)
On 22 Feb 2010, at 19:36, Jiří Procházka wrote: I wonder if we as a group of people interested in Semantic Web could come up with etiquette for ontology mapping. Interesting topic! My €0.02: If the other vocabulary is likely to be - more stable - more mature - more likely to be widely used - more likely to be around for a longer time then you should map your terms to it. If not, don't. So IMO the rdfg vocabulary should map to the SPARQL Service Description vocabulary as soon as it becomes REC, but SPARQL-SD should NOT map to rdfg. Hi Richard, that also seems reasonable to me at first, but when thinking about it more thoroughly, there is value in both ontologies doing the mapping to the other. Yes, if both sides agree, then two-way mappings are great. But this is only realistic if both vocabularies rate about equally on the criteria above. As an extreme example, it would be totally unrealistic to expect the RDFS vocabulary to link back to every vocabulary that has some sort of label/name property (all of which should be subproperties of rdfs:label). Certain mapping statements make sense from PoV of one ontology, but not the other. I don't know what you mean. An example might help. But anyway, if you map to my ontology, but from my POV that mapping doesn't make sense, then I'm certainly not going to map back to yours. If we allow ourselves to go a bit further, I thought it would be great if there was some community developed service which would in automated fashion give advice for improvement and rate user submitted (better yet WoD collected) ontologies judging their quality of design - most importantly re-usability which basically means how is it aligned to other similar ontologies. This would be probably very difficult, at least because of varying opinions on this... I guess database community has something to say about that. I think that's a different issue. When it comes to rating the “quality” of a vocabulary, then the amount of mappings to other vocabularies is a very minor factor. First, because other things (especially amount of uptake and strength of the surrounding community) are much more important. Second, because adding the mappings is so easy. No vocabulary will succeed or fail because of its inclusion or lack of mappings. Nevertheless, I agree that we need services that support us in finding high-quality vocabularies, and that help drive the improvement of existing ones. But it's a complex subject, there are many existing efforts (Watson, Talis Schema Cache, Falcons Concept Search, ontologydesignpatterns.org, and I probably missed a few), and to me it's not obvious what is the right approach. Perhaps we don't need better ways of finding and creating vocabularies, but better ways of finding and creating communities around a domain that can then jointly agree on a vocabulary. All the best, Richard There are more things to talk about regarding this, but this is what I have in mind so far. Best, Jiri Best, Richard Best, Jiri Hope that helps. thanks, .greg [1] http://www.w3.org/TR/sparql11-service-description/#id41794
ontology mapping etiquette (was What is the class of a Named Graph?)
On 02/22/2010 01:53 PM, Richard Cyganiak wrote: > Jiri, > > On 22 Feb 2010, at 10:51, Jiří Procházka wrote: >> I wonder if we as a group of people >> interested in Semantic Web could come up with etiquette for ontology >> mapping. > > Interesting topic! My €0.02: If the other vocabulary is likely to be > > - more stable > - more mature > - more likely to be widely used > - more likely to be around for a longer time > > then you should map your terms to it. If not, don't. > > So IMO the rdfg vocabulary should map to the SPARQL Service Description > vocabulary as soon as it becomes REC, but SPARQL-SD should NOT map to rdfg. Hi Richard, that also seems reasonable to me at first, but when thinking about it more thoroughly, there is value in both ontologies doing the mapping to the other. Danbri recently touched on this on IRC in relation to reciprocal WebID owl:sameAs relations. What one source says in RDF is what it considers true, which in our case would also mean the mapping makes sense from the point of view of both ontologies if reciprocal. So I would advocate doing reciprocal mappings, if they can agree on the common mapping. This brings another issue... Certain mapping statements make sense from PoV of one ontology, but not the other. Should it be dropped and just have the both-sides-approved mapping? I'm in favour of publishing it on just with the ontology for which it makes sense. Dumping it would encourage one-big-federated-web-ontology which is nice dream but not what I believe is suitable for the real world and web (thanks to its relativistic nature). If we allow ourselves to go a bit further, I thought it would be great if there was some community developed service which would in automated fashion give advice for improvement and rate user submitted (better yet WoD collected) ontologies judging their quality of design - most importantly re-usability which basically means how is it aligned to other similar ontologies. This would be probably very difficult, at least because of varying opinions on this... I guess database community has something to say about that. There are more things to talk about regarding this, but this is what I have in mind so far. Best, Jiri > Best, > Richard > > >> >> Best, >> Jiri >> >>> >>> Hope that helps. >>> >>> thanks, >>> .greg >>> >>> >>> [1] http://www.w3.org/TR/sparql11-service-description/#id41794 >>> >> > signature.asc Description: OpenPGP digital signature
Re: What is the class of a Named Graph?
Jiri, On 22 Feb 2010, at 10:51, Jiří Procházka wrote: I wonder if we as a group of people interested in Semantic Web could come up with etiquette for ontology mapping. Interesting topic! My €0.02: If the other vocabulary is likely to be - more stable - more mature - more likely to be widely used - more likely to be around for a longer time then you should map your terms to it. If not, don't. So IMO the rdfg vocabulary should map to the SPARQL Service Description vocabulary as soon as it becomes REC, but SPARQL-SD should NOT map to rdfg. Best, Richard Best, Jiri Hope that helps. thanks, .greg [1] http://www.w3.org/TR/sparql11-service-description/#id41794
Re: What is the class of a Named Graph?
On 02/22/2010 05:54 AM, Gregory Williams wrote: > On Feb 21, 2010, at 5:29 AM, Michael Hausenblas wrote: > >>> What you pointed at is a property sd:namedGraph. >> >> Well spotted! But I didn't really say: here is the class name. I wanted to >> point out that there is something relevant, likely be part of an upcoming >> standard so one should have it in mind. Sorry for not being explicit enough >> in the first place ;) >> >>> The upcoming SPARQLstandard doesn't define any class for named graphs. >> >> Not yet. Any news from this end, Greg? > > The next draft of the service description document will likely include a > named graph class to go along with the property mentioned above. If the > modeling in the example section[1] works for the named graphs you're hoping > to describe (the named graph pointed to by the sd:namedGraph property), then > the new class will probably be what you're after. I wonder if it would owl:equivalentClass the rdfg:Graph. Ontology mapping is important or the main advantage of RDF over XML and such is lost. I guess no W3C standard did that yet. Anyway the RDFG has prior act. I wonder if we as a group of people interested in Semantic Web could come up with etiquette for ontology mapping. Best, Jiri > > Hope that helps. > > thanks, > .greg > > > [1] http://www.w3.org/TR/sparql11-service-description/#id41794 > signature.asc Description: OpenPGP digital signature
Re: What is the class of a Named Graph?
On Feb 21, 2010, at 5:29 AM, Michael Hausenblas wrote: >> What you pointed at is a property sd:namedGraph. > > Well spotted! But I didn't really say: here is the class name. I wanted to > point out that there is something relevant, likely be part of an upcoming > standard so one should have it in mind. Sorry for not being explicit enough > in the first place ;) > >> The upcoming SPARQLstandard doesn't define any class for named graphs. > > Not yet. Any news from this end, Greg? The next draft of the service description document will likely include a named graph class to go along with the property mentioned above. If the modeling in the example section[1] works for the named graphs you're hoping to describe (the named graph pointed to by the sd:namedGraph property), then the new class will probably be what you're after. Hope that helps. thanks, .greg [1] http://www.w3.org/TR/sparql11-service-description/#id41794
Re: What is the class of a Named Graph?
> What you pointed at is a property sd:namedGraph. Well spotted! But I didn't really say: here is the class name. I wanted to point out that there is something relevant, likely be part of an upcoming standard so one should have it in mind. Sorry for not being explicit enough in the first place ;) > The upcoming SPARQLstandard doesn't define any class for named graphs. Not yet. Any news from this end, Greg? Cheers, Michael -- Dr. Michael Hausenblas LiDRC - Linked Data Research Centre DERI - Digital Enterprise Research Institute NUIG - National University of Ireland, Galway Ireland, Europe Tel. +353 91 495730 http://linkeddata.deri.ie/ http://sw-app.org/about.html > From: Jiří Procházka > Date: Sun, 21 Feb 2010 10:51:16 +0100 > To: Michael Hausenblas > Cc: , Linked Data community > Subject: Re: What is the class of a Named Graph? > > What you pointed at is a property sd:namedGraph. The upcoming SPARQL > standard doesn't define any class for named graphs. > I support using: http://www.w3.org/2004/03/trix/rdfg-1/Graph > > Best, > Jiri > > On 02/21/2010 10:40 AM, Michael Hausenblas wrote: >> >> Nathan, >> >>> Any further input before I start using rdfg-1:Graph when describing graphs? >> >> I'd suggest you forget about both references and go with the upcoming >> SPARQL standard [1]. >> >> Cheers, >> Michael >> >> [1] >> http://www.w3.org/TR/2010/WD-sparql11-service-description-20100126/#id41744 >> >
Re: What is the class of a Named Graph?
What you pointed at is a property sd:namedGraph. The upcoming SPARQL standard doesn't define any class for named graphs. I support using: http://www.w3.org/2004/03/trix/rdfg-1/Graph Best, Jiri On 02/21/2010 10:40 AM, Michael Hausenblas wrote: > > Nathan, > >> Any further input before I start using rdfg-1:Graph when describing graphs? > > I'd suggest you forget about both references and go with the upcoming > SPARQL standard [1]. > > Cheers, > Michael > > [1] > http://www.w3.org/TR/2010/WD-sparql11-service-description-20100126/#id41744 > signature.asc Description: OpenPGP digital signature
Re: What is the class of a Named Graph?
Nathan, > Any further input before I start using rdfg-1:Graph when describing graphs? I'd suggest you forget about both references and go with the upcoming SPARQL standard [1]. Cheers, Michael [1] http://www.w3.org/TR/2010/WD-sparql11-service-description-20100126/#id41744 -- Dr. Michael Hausenblas LiDRC - Linked Data Research Centre DERI - Digital Enterprise Research Institute NUIG - National University of Ireland, Galway Ireland, Europe Tel. +353 91 495730 http://linkeddata.deri.ie/ http://sw-app.org/about.html > From: Nathan > Organization: webr3 > Reply-To: > Date: Sun, 21 Feb 2010 00:38:39 + > To: Linked Data community > Subject: What is the class of a Named Graph? > Resent-From: Linked Data community > Resent-Date: Sun, 21 Feb 2010 00:39:24 + > > Hi All, > > As the subject line goes - what is the (recommended) rdfs:Class of a > Named Graph? Thus far I can only see: > > a: http://www.w3.org/2004/03/trix/rdfg-1/Graph > b: http://sw.nokia.com/RDFQ-1/Graph > > Where [a] is used as the domain of swp:Warrant,Authority etc. > > Any further input before I start using rdfg-1:Graph when describing graphs? > > Many Regards, > > Nathan > >
Re: What is the class of a Named Graph?
On 21 Feb 2010, at 01:38, Nathan wrote: > Hi All, > > As the subject line goes - what is the (recommended) rdfs:Class of a > Named Graph? Thus far I can only see: > > a: http://www.w3.org/2004/03/trix/rdfg-1/Graph I could dereference this and find it's meaning. > b: http://sw.nokia.com/RDFQ-1/Graph I could not dereference this. So a: is the one to use. Henry > > Where [a] is used as the domain of swp:Warrant,Authority etc. > > Any further input before I start using rdfg-1:Graph when describing graphs? > > Many Regards, > > Nathan > >
What is the class of a Named Graph?
Hi All, As the subject line goes - what is the (recommended) rdfs:Class of a Named Graph? Thus far I can only see: a: http://www.w3.org/2004/03/trix/rdfg-1/Graph b: http://sw.nokia.com/RDFQ-1/Graph Where [a] is used as the domain of swp:Warrant,Authority etc. Any further input before I start using rdfg-1:Graph when describing graphs? Many Regards, Nathan
