- From: Ivan Herman <ivan@w3.org>
- Date: Mon, 16 Jul 2007 13:32:57 +0200
- To: Giorgos Stoilos <gstoil@image.ece.ntua.gr>
- Cc: Peter.Vojtas@mff.cuni.cz, 'Ken Laskey' <klaskey@mitre.org>, public-xg-urw3@w3.org, mpool@convera.com
- Message-ID: <469B5769.8000401@w3.org>
Giorgos Stoilos wrote: > Hi Peter, > > Triples syntax is very specific to the RDF standard and *not* to every W3C > standard. For example, triples syntax is not used in OWL (the standard > describes a mapping to RDF graphs but a) it is very limited and cannot > capture the OWL Semantics b) other syntaxes are preferred), ??? why is the mapping limited? Also: OWL is not equal to OWL-DL. OWL Full is fully described and defined in terms of an extension of RDF semantics, and the there is a very clear mapping between the OWL DL semantics and the corresponding OWL Full semantics. However: we indeed have to separate two things. There is a 'syntax', essentially RDF/XML, which is nothing more than what it says: syntax. And there is the triple model. Indeed, in some cases other _syntaxes_ are preferred. But that is a secondary issue in my view. > while RIF will > not care about triples syntax at all. > This _may_ become correct if you refer to the RDF/XML syntax. It is not correct if you refer to the model of RDF triples. > I think you are mixing two issues here. > 1) The specification of an uncertainty ontology, which describes the > concepts and their relations, i.e. the schema, i.e. the TBox. So I don't see > why we should add instances (ABox) in the ontology. At least in my > understanding the Ontology is *not* meant to describe how to capture > uncertainty in practice. > 2) How to extend ontology languages, like OWL, to add uncertainty. Then we > should take into account instances and thus the ABox and thus your example > below has a purpose. > So I don't understand how reification fits with the Uncertainty Ontology. > > Now, taken that triples are used in RDF (and not in OWL) I see your example > below as an effort to extend RDF as to capture uncertainty, or about > serializing an Uncertainty-OWL extension to RDF triples, which I don't see > how is relevant. > > -gstoil > >> -----Original Message----- >> From: public-xg-urw3-request@w3.org [mailto:public-xg-urw3-request@w3.org] >> On Behalf Of Peter Vojtas >> Sent: Monday, July 16, 2007 11:24 AM >> To: Ken Laskey >> Cc: public-xg-urw3@w3.org; mpool@convera.com >> Subject: [URW3 public] Re: [URW3] ... three questions based on the last >> telecon >> >> >> Dear colleaguess (sent to public list and separately to KL and MP), >> >> as I have pointed in the ontology page in Top Level comments by P. >> Vojtas is there a mistake?, see >> http://www.w3.org/2005/Incubator/urw3/wiki/is_there_a_mistake%3F >> >> by W3C standards, basic information unit is a triple (subject, >> predicate, object) which can be true or false in a structure (to avoid >> discussion whether it is a sentence or proposition, w3c uses statement). >> >> see e.g. http://www.w3.org/TR/rdf-primer/ for following example >> >> http://www.example.org/index.html has a creation-date whose value is >> August 16, 1999 >> >> here we can use reification for another writing asigning an identifier >> to the statement >> >> ex:triple1 rdf:type rdf:Statement >> ex:triple1 rdf:subject http://www.example.org/index.html >> ex:triple1 rdf:predicate http://purl.org/dc/elements/1.1/creator >> ex:triple1 rdf:object http://www.example.org/staffid/85740 >> ex:triple1 ex:creator http://www.example.org/staffid/85741 >> >> THIS CONSTRUCTION IS VERY USEFULL IN OUR CASE >> >> especialy in our ontology discussion the triple >> >> urw3:Sentence urw3:hasUncertainty urw3:Uncertainty >> >> should be by my opinion rewritten as >> >> urw3:triple2 rdf:type rdf:Statement >> urw3:triple2 rdf:subject urw3:Sentence >> urw3:triple2 rdf:predicate urw3:hasUncertainty >> urw3:triple2 rdf:object urw3:Uncertainty >> urw3:triple2 ex:creator urw3:Mitch >> >> and instance ( consider also an "instance" ex:triple1 >> urw3:hasUncertainty urw3:0.9) >> >> as, e.g. >> >> urw3:triple3 rdf:type rdf:Statement >> urw3:triple3 rdf:subject ex:triple1 >> urw3:triple3 rdf:predicate urw3:hasUncertainty >> urw3:triple3 rdf:object urw3:0.9 >> urw3:triple3 ex:creator urw3:Peter >> urw3:triple3 urw3:tool urw3:Bayes >> >> The example with the german sentence (Mathias can help) is very usefull >> (words morgen and Morgen are problematic) because it shows what can >> happen. MP assigns an uncertainty to his own translation by expression >> "if I've translated correctly". Nevertheless, by my opinion "Es regnet >> morgen" is a problematic sentence because "Es regnet" is about present >> and "morgen" with lower case m in the begining means tomorrow, it is an >> adverb. So a problem accurs, what to do with a gramaticaly wrong >> sentence (note that the word sentence I use here in the linguistical >> sense, which in the W3c terminology can by defined appropriately by >> corresponding triples, by defining predicates like subject, verb, >> object, mode (manner), place and time). I would say either "Es regnet >> heute morgen" or "Es wird morgen regnen". >> >> Sorry for such a long mail, concluding I would like to say, please let >> us use w3c terminology (arguing for necessity of an extensions of >> standards we need be compatible with current standards). Next, the above >> example shows we need to define our own prefix and rdf vocabulary for >> uncertainty ontology. >> >> Greetings Peter >> >> >> >>> *From:* Mike Pool >>> *Sent:* Friday, July 13, 2007 3:25 PM >>> *To:* public-xg-urw3-request@w3.org >>> *Subject:* three questions based on the last telecon. >>> >>> Hi, all: >>> >>> We've been having some great discussions during the meetings and I'd >>> like to pick up a few threads that came up in the last meeting. I >>> reread these as I was trying to write up the minutes: >>> >>> 1) >>> Peter suggested that we use w3c standards as our guide for the >>> meaning of 'proposition'. Peter, do you know if this is defined >>> somewhere by the w3C. Could you point us to the definition? >>> >>> 2) >>> I argued that propositions, in the sense of the meaning of a >>> sentence that is invariant through all the paraphrases and >>> translations of the sentence, rather than assertions or sentences as >>> the kinds of things that hold probability values. >>> >>> Kathy noted in the meeting that a problem with this definition is >>> that a system might assign different uncertainty values to 2 >>> different logically equivalent sentences. I can imagine that this >>> is possible, but where it occurs I would think it nothing more than >>> a weakness in the system, not in the definition I've suggested. For >>> example, I might misunderstand 'Es regnet morgen' as 'it will rain >>> this morning' rather than 'it will rain tomorrow' (if I've >>> translated correctly) and assign it a different probability value >>> than that which I'm assigning to 'it will rain tomorrow'. But I >>> think that anyone who observed my doing this would point out that >>> it's a contradiction, i.e., that since these things have the same >>> meaning, I'm obligated to assign them the same probability value. >>> In other words, it is in virtue of their representing the same >>> proposition that I'm obligated to assign them the same probability >>> value. So, I think this only helps to underscore the fact that >>> when we explore our intuitions, we believe that propositions are the >>> real p.v. holders. >>> >>> 3) >>> Anne, you said at one point that "not all beliefs can appropriately >>> be represented as numerical values" and that it "glosses over >>> inconsistencies - beliefs may be logically incompatible". I was >>> intrigued by the suggestion, can you say more? >>> >>> >>> Again, thanks all for a stimulating telecon on Wednesday. Apologies >>> in advance if this address is not the right forum for these >>> discussions. >>> >>> Best regards, >>> >>> Mike Pool >>> >>> -------------------------------- >>> >>> >>> >>> ------------------------------------------------------------------------ >> ----- >>> Ken Laskey >>> MITRE Corporation, M/S H305 phone: 703-983-7934 >>> 7151 Colshire Drive fax: 703-983-1379 >>> McLean VA 22102-7508 >>> > > > -- Ivan Herman, W3C Semantic Web Activity Lead URL: http://www.w3.org/People/Ivan/ PGP Key: http://www.cwi.nl/%7Eivan/AboutMe/pgpkey.html FOAF: http://www.ivan-herman.net/foaf.rdf
Received on Monday, 16 July 2007 11:32:59 UTC