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[protege-owl] Modeling change, source, uncertainty, contradiction?

Claudia Elena Arenas Corona clao_17 at hotmail.com
Fri Aug 24 18:08:28 PDT 2007



I'm Claudia, and I want start use protege, anybody that help me?> Date: Wed, 22 Aug 2007 15:11:58 +0200> From: johann.petrak at chello.at> To: protege-owl at lists.stanford.edu> Subject: Re: [protege-owl] Modeling change, source, uncertainty, contradiction?> > Matt Williams wrote:> > As a very simple approach to modelling time, you could use > > time-interval-valid versions of the ontology. Not pretty, but might be > > enough.> > > > For my purpose, I would be more interested in searchability than> deductability. In other words, I do not want to make deductions based> on time -- it would be sufficient to find properties of instances> that are valid at a specific time. (So time would not be an issue> for classes, just for instances)> Naively I want an attribute "valid during" for each property/relation> between instances.> More generically I want several attributs: "valid during", "source"> etc.> The only thing I would need to do is to get the value of these> attributes out of the knowledge base and to search for triples> where these attributes match a specific pattern.> > > DL ontologies will not handle conflicting information. To do that, you > > need to use a defeasible formalism. There is a little bit of work on > > ontologies & defeasibel reasoning.> > > > I have used argumentation & ontologies; there's a paper at > > http://acl.icnet.uk/~mw/WillliamsHunterICTAI07.pdf which also has > > references to the other approaches.> Thank you for the reference. I am not sure I need it at such a> complex level though, since I do not need a reasoner to> come up with sets of entailed or conflicting facts.> > I think it would be sufficient for me to be able to model> something like> "source A indicates instanceX Rel1 instanceY"> "source B indicates instanceX notRel1 instanceY"> or put differently> instanceX Rel1-withattr: from source A instanceY> etc.> > So it comes down to attatching searchable arbitrary attributes> to properties/relations again.> > Could it be that I am missing something totally elementary> here because it seems that should be something that is needed> all the time?> > Cheers,> Johann> > > > If you want to discuss this in more detail, email me off-list.> > > > HTH,> > > > Matt> > > > Johann Petrak wrote:> >> I am pretty new to using Ontologies for knowledge represenation so> >> most of the tutorials and examples I have seen only are about> >> modeling some consistent set of unchanging facts.> >>> >> However, in real word situations it is often necessary to deal> >> with knowledge or information that has one of the following> >> complications:> >>> >> * a fact might change over time. More exactly, a property> >> might be valid during some period of time but not another.> >> Is it possible to model this in OWL ontologies and if yes,> >> what are common design patterns to do it?> >>> >> * The fact that some instance has some property might be> >> known based on sources A and B but might not be confirmed> >> from source C. More problematic, it might contradict> >> information from source D. So instead of some fact just> >> "existing" we would like to model that it exists> >> "according to source A" but "not confirmed by source C"> >> and "not, according to source D"> >> Is it possible to model this?> >>> >> * Sometimes it would be useful to attach a level of belief> >> to a fact. E.g. some instance having some property might> >> be likely but not certain.> >>> >> These things are probably differently hard to model, if at> >> all.> >> My biggest concern at the moment is change over time: for> >> most applications where I need some knowledge representation> >> it would be extremely important to be able to know that> >> e.g. some name was used during a certain time or that some> >> property existed during a certain period but not another.> >>> >> I would be thankful for any hints you could give me or> >> any papers or sources you could point out where these> >> issues are discussed.> >>> >> Johann> >>> >> _______________________________________________> >> protege-owl mailing list> >> protege-owl at lists.stanford.edu> >> https://mailman.stanford.edu/mailman/listinfo/protege-owl> >>> >> Instructions for unsubscribing: http://protege.stanford.edu/doc/faq.html#01a.03 > > _______________________________________________> > protege-owl mailing list> > protege-owl at lists.stanford.edu> > https://mailman.stanford.edu/mailman/listinfo/protege-owl> > > > Instructions for unsubscribing: http://protege.stanford.edu/doc/faq.html#01a.03 > > > _______________________________________________> protege-owl mailing list> protege-owl at lists.stanford.edu> https://mailman.stanford.edu/mailman/listinfo/protege-owl> > Instructions for unsubscribing: http://protege.stanford.edu/doc/faq.html#01a.03 
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