<p dir="ltr">Question: isn't it possible to 'aggregate' classes of subjects in respect to the properties / predicates some set of subjects have in common. Example: a Person class subjects would have 'birthPlace', 'birthDate' and 'name' properties and an Artist subclass would have those properties of Person plus 'creatorOf' properties of artworks objects. So a superclass would have a superset of the properties of a subclass.</p>
<p dir="ltr">Sorry for my ignorance. Best,<br>
Sebastian.</p>
<p dir="ltr">> On Jul 6, 2017 3:30 PM, <<a href="mailto:jaccoud@petrobras.com.br">jaccoud@petrobras.com.br</a>> wrote:<br>
>><br>
>> Virtus in medium est.<br>
>><br>
>> I agree that by any standard, the DBpedia Ontology is messy, and needs some work. Otherwise, it would be only a list of concepts with almost no relations between them. These relations (the subconcept hierarchy and other relevant relations defined by the authors of the ontology) need to be there if the ontology is to be useful to something more than mere documentation.<br>
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>> However, a well sound ontology needs a LOT of work, and the wider the scope, the harder it is to get it right. Since DBpedia has no scope boundaries, the amount of work to select a suitable foundational ontology and expand it would be huge. No, I'm not quoting Trump, it is really huge. <br>
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>> What DBpedia needs is a few abstract notions without commitment to any foundational ontology, since the tradeoffs each FO makes would hurt DBpedia genericity. For example, different groups may fight years about an exact definition of "Software", but most will agree it is a intelectual product, such as a romance, a song or a theater play. The ontology should reflect that, without getting in details about how software is encoded, versioned, reified etc., since these details are important only to applications dealing with the concept of software, and not for DBpedia itself. <br>
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>> A few months ago, I complained that ComputerLanguage was not a subconcept of Language, and it was promptly corrected, since it is very hard do disagree with that. There are a lot of places where such refactoring is needed, and I think it would help a lot. Further refining, such as creating subclasses of ComputerLanguage, should be avoided in the name of keeping the ontology simple and generic. Upper-level classes are needed to sort things out, but one should also avoid defining things like disjointness because it would lead to stuff like partition completeness and other stuff which are clearly not needed for the purposes of DBpedia.<br>
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>> But I agree a cleanup is needed, since a lot of dbo:Things don't make much sense.<br>
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>> Cheers.<br>
>> =============================================<br>
>> Marcelo Jaccoud Amaral<br>
>> Petrobras, Brazil<br>
>> =============================================<br>
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>> De: "Paul Houle" <<a href="mailto:paul.houle@ontology2.com">paul.houle@ontology2.com</a>><br>
>> Para: "John Flynn" <<a href="mailto:jflynn12@verizon.net">jflynn12@verizon.net</a>>, "'Sebastian Hellmann'" <<a href="mailto:hellmann@informatik.uni-leipzig.de">hellmann@informatik.uni-leipzig.de</a>>, "'semantic-web at W3C'" <<a href="mailto:semantic-web@w3c.org">semantic-web@w3c.org</a>>, 'public-lod' <<a href="mailto:public-lod@w3.org">public-lod@w3.org</a>>, 'DBpedia' <<a href="mailto:Dbpedia-discussion@lists.sourceforge.net">Dbpedia-discussion@lists.sourceforge.net</a>><br>
>> Data: 2017-07-06 12:25<br>
>> Assunto: Re: [DBpedia-discussion] Call for Ontology Editor demos for DBpedia<br>
>> ________________________________<br>
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>> I would disagree.<br>
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>> The DBpedia Ontology is not designed to support any specific kind of reasoning. <br>
>><br>
>> What it *is* designed to do is capture the somewhat structured data that exists in Wikipedia. Following the much misunderstood "semantic web", the emphasis is on properties first, and then classes second. Think of it as a set of baseball or Pokemon cards; the point is not to replicate or even closely describe the performance or rules of the game, but to go after the long hanging fruit of "things that are easy to ontologize."<br>
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>> There is a real price to pay for this; from the viewpoint of conventional application development and introductory computer science, the data is not always factually correct or satisfies the invariants required for a particular algorithm. Practically that means that you might ask for "US States" and get 48 or 51, that somebody like Barry Bonds or Mel Gibson has their career much better represented than J. Edgar Hoover or J. Eric S. Thompson, and you would probably find that the "tree of life" in DBpedia is not really a tree.<br>
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>> If you need to reasoning in some domain you need to find some area you are willing to pump the entropy out of, create the data structures appropriate for what you want to do, and possibly incorporate data from DBpedia, doing whatever cleanup is necessary. That's not different at all from the situation of "doing reasoning over reasoning over data collected by a large organization".<br>
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>> ------ Original Message ------<br>
>> From: "John Flynn" <<a href="mailto:jflynn12@verizon.net">jflynn12@verizon.net</a>><br>
>> To: "'Sebastian Hellmann'" <<a href="mailto:hellmann@informatik.uni-leipzig.de">hellmann@informatik.uni-leipzig.de</a>>; "'semantic-web at W3C'" <<a href="mailto:semantic-web@w3c.org">semantic-web@w3c.org</a>>; "'public-lod'" <<a href="mailto:public-lod@w3.org">public-lod@w3.org</a>>; "'DBpedia'" <<a href="mailto:Dbpedia-discussion@lists.sourceforge.net">Dbpedia-discussion@lists.sourceforge.net</a>><br>
>> Sent: 7/5/2017 11:43:02 AM<br>
>> Subject: Re: [DBpedia-discussion] Call for Ontology Editor demos for DBpedia<br>
>><br>
>> I have long been curious about the DBpedia ontology structure so I just took a look at the ontology represented in (<a href="https://dl.dropboxusercontent.com/u/375401/dbo_no_mappings.nt">https://dl.dropboxusercontent.com/u/375401/dbo_no_mappings.nt</a>) as referenced in the email below.<br>
>> I normally start the evaluation of an ontology by looking at the top-down class relationships. So, I did a search for the classes that were listed as a direct subclass of owl#Thing to get a general idea of the organization of the DBpedia class structure.<br>
>> To say the least, I was sorely disappointed. Here are a few of the DBpedia classes that are direct subclasses of owl#Thing: Food, Media, Work, Blazon, Altitude, Language, Currency, Statistic, Diploma, Award, Agent, PublicService, Disease, GrossDomesticProdutPerCapita, ElectionDiagram, Demographics, Relationship, Medicine, List, BioMolecule. I gave up after this small sample. It is obvious that the DBpedia community needs to worry a lot more about the structure of the ontology itself rather than focusing on selecting a new editor. A working group needs to be established to go back to the drawing board and look at the DBpedia ontology form the top down. It certainly doesn't make much sense as it is currently structured.<br>
>> <br>
>> John Flynn<br>
>> <a href="http://semanticsimulations.com">http://semanticsimulations.com</a><br>
>><br>
>> <br>
>> From: Sebastian Hellmann [mailto:<a href="mailto:hellmann@informatik.uni-leipzig.de">hellmann@informatik.uni-leipzig.de</a>] <br>
>> Sent: Wednesday, July 05, 2017 10:43 AM<br>
>> To: 'semantic-web at W3C'; public-lod; DBpedia<br>
>> Subject: [DBpedia-discussion] Call for Ontology Editor demos for DBpedia<br>
>> <br>
>><br>
>> Dear all,<br>
>><br>
>> we are preparing a switch from the mappings wiki (<a href="http://mappings.dbpedia.org">http://mappings.dbpedia.org</a>) to another ontology editor and started to collect requirements/tools here:<br>
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>> <a href="https://docs.google.com/document/d/1HwtJJ3jIlrQAPwHYhvpw4a4Z4hZorTGaZTB8Bq8Y-TI/edit">https://docs.google.com/document/d/1HwtJJ3jIlrQAPwHYhvpw4a4Z4hZorTGaZTB8Bq8Y-TI/edit</a><br>
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>> We already have a demo for Webprotege thanks to Ismael Rodriguez, our GSoC student. As we are lacking time and resources, we will probably only consider editors with a running demo, so the community can try it. <br>
>> Our main interest is of course to manage the DBpedia core ontology and push any mappings to other ontologies in separate files. So we provide a core version for demo purposes created with: <br>
>> rapper -g dbpedia_2016-10.nt | grep -v '\(<a href="http://schema.org">http://schema.org</a>\|<a href="http://www.wikidata.org">http://www.wikidata.org</a>\|<a href="http://www.ontologydesignpatterns.org">http://www.ontologydesignpatterns.org</a>\)' > dbo_no_mappings.nt<br>
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>> <a href="https://dl.dropboxusercontent.com/u/375401/dbo_no_mappings.nt">https://dl.dropboxusercontent.com/u/375401/dbo_no_mappings.nt</a><br>
>> (I hope that the regex didn't kick out anything essential or broke any axioms...)<br>
>><br>
>> We would be very happy, if anyone from the semantic web community would make a demo with their favorite editor and add a link to the Google Doc and post a short message on the DBpedia discussion list[1] or on slack <a href="https://dbpedia.slack.com/">https://dbpedia.slack.com/</a>.<br>
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>> This would help us to make a more informed decision. The next DBpedia Dev online meeting will be on 2nd of August 14:00 (each first Wednesday per month). Presentations of editors are also welcome. We will also discuss the editor question during the DBpedia meeting in Amsterdam, co-located with SEMANTiCS on 14.9. <a href="http://wiki.dbpedia.org/meetings/Amsterdam2017">http://wiki.dbpedia.org/meetings/Amsterdam2017</a><br>
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>> Thank you for your help! <br>
>><br>
>> [1] <a href="https://sourceforge.net/projects/dbpedia/lists/dbpedia-discussion">https://sourceforge.net/projects/dbpedia/lists/dbpedia-discussion</a><br>
>><br>
>> -- <br>
>> All the best,<br>
>> Sebastian Hellmann<br>
>><br>
>> Director of Knowledge Integration and Linked Data Technologies (KILT) Competence Center<br>
>> at the Institute for Applied Informatics (InfAI) at Leipzig University<br>
>> Executive Director of the DBpedia Association<br>
>> Projects: <a href="http://dbpedia.org">http://dbpedia.org</a>, <a href="http://nlp2rdf.org">http://nlp2rdf.org</a>, <a href="http://linguistics.okfn.org">http://linguistics.okfn.org</a>, <a href="https://www.w3.org/community/ld4lt">https://www.w3.org/community/ld4lt</a><br>
>> Homepage: <a href="http://aksw.org/SebastianHellmann">http://aksw.org/SebastianHellmann</a><br>
>> Research Group: <a href="http://aksw.org------------------------------------------------------------------------------">http://aksw.org------------------------------------------------------------------------------</a><br>
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