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Well, I hope that folks who care will look at the slides, because the 
slides say exactly what I said, with phrases like "ensures consistency" 
and the conclusion that there is no difference between an AP and OWL.

And thanks for pointing to the slides -- I hadn't had a link before, and 
I think they'll be worth quoting in some things I'm working on.

kc


On 7/27/14, 9:21 AM, Gordon Dunsire wrote:
>
> Karen
>
> I agree that the use of "constraint" in RDF and OWL documentation is 
> misleading - but then that is why the expression of "what we mean" in 
> RDF is so useful for data and applications in bibliographic 
> information retrieval services which deal explicitly with the way 
> humans label things :-)
>
> I and other members of the FRBR Review Group have read that 
> documentation, and we hope we have understood it correctly. As far as 
> I know, we have never claimed that the declaration of property 
> cardinality constraints, or indeed domains and ranges, is a data 
> validation technique.
>
> However, I think the declaration of the intentions of a model, schema, 
> ontology, or whatever you want to call it, in RDF is highly desirable 
> as a first step in developing applications for data that purport to 
> follow the model. That was the context of my presentation in Lisbon 
> [1][2]. I recall that the dominant topic in the discussion that 
> followed was the meaning of "constraint" and data validation rather 
> than the questions I raised in the presentation, so they remain 
> unanswered :-(
>
> So I can say that it is the intention of the FRBR Review Group to 
> express the model using OWL cardinality constraints. The automatic 
> identification of "sameAs" instances of Works and Manifestations by 
> reasoners will be useful, for example, in applications that bring 
> together FRBR-conformant data from multiple local sources. It may well 
> be useless or harmful to other applications; I think it is up to the 
> application. I repeat, if there is anything wrong with this, please 
> (anyone) let us know!
>
> Is there a specific reason you say "[the "realizes" relationship 
> between FRBRer:expression and FRBRer:work has owl:qualifiedCardinality 
> "1"] does not conform, AFAIK, to the E-R analysis in FRBR"? I think it 
> is fairly clear from the FRBR report containing the results of 
> applying E-R techniques that "one and only one" is the intended 
> cardinality between Expression and Work, and Item and Manifestation.
>
> Cheers
>
> Gordon
>
> [1] The FRBR ontology (pptx with animation): 
> http://www.gordondunsire.com/pubs/pres/FRBROWL.pptx
>
> [2] The FRBR ontology (pdf with no animation): 
> http://dcevents.dublincore.org/IntConf/dc-2013/paper/view/139/158
>
> *From:*Bibliographic Framework Transition Initiative Forum 
> [mailto:[log in to unmask]] *On Behalf Of *Karen Coyle
> *Sent:* 26 July 2014 23:29
> *To:* [log in to unmask]
> *Subject:* Re: [BIBFRAME] BF vocabulary and RDA
>
> On 7/26/14, 2:27 AM, Gordon Dunsire wrote:
>
>     This is what FRBR actually says: “The methodology used in this
>     study is based on an entity analysis technique that is used in the
>     development of conceptual models for relational database systems.
>     Although the study is not intended to serve directly as a basis
>     for the design of bibliographic databases, the technique was
>     chosen as the basis for the methodology because it provides a
>     structured approach to the analysis of data requirements that
>     facilitates the processes of definition and delineation that were
>     set out in the terms of reference for the study.”
>
>     I don’t think that’s quite the same thing. In any case, a
>     normalized RDBMS is a very good fit indeed with the RDF world;
>     see, for example, the work of the W3C RDB2RDF Working Group [1].
>
>
> This is all very complex, and I hardly feel that it can be adequately 
> covered in an email exchange, nor that I can give the absolute, 
> definitive answer. It also may be too orthogonal to the concerns of 
> most people on this list. However, I will try, and welcome others to 
> weigh in.
>
> ***
> tl;dr: 1) E-R and RDF have some similarities, but are not semantically 
> the same, especially in how they define "class" 2) OWL is not a 
> constraint language for instance data, but a language for testing axioms
> ***
>
> First, I'd disagree with "very good fit." In fact, that documentation 
> says:
>
> " Is the RDF model an entity-relationship mode? Yes and no. It is 
> great as a basis for ER-modelling, but because RDF is used for other 
> things as well, RDF is more general. RDF is a model of entities 
> (nodes) and relationships. If you are used to the "ER" modelling 
> system for data, then the RDF model is basically an openning of the ER 
> model to work on the Web. In typical ER model involved entity types, 
> and for each entity type there are a set of relationships (slots in 
> the typical ER diagram). The RDF model is the same, except that 
> relationships are first class objects: they are identified by a URI, 
> and so anyone can make one. Furthurmore, the set of slots of an object 
> is not defined when the class of an object is defined. The Web works 
> though anyone being (technically) allowed to say anything about 
> anything. This means that a relationship between two objects may be 
> stored apart from any other information about the two objects. This is 
> different from object-oriented systems often used to implement ER 
> models, which generally assume that information about an object is 
> stored in an object: the definition of the class of an object defines 
> the storage implied for its properties. " [1]
>
> The exceptions noted here are significant. Yes, you can transform an 
> RDBMS or an E-R model to RDF for the convenience of working within the 
> RDF world. But note that both RDF and OWL documentation caution 
> against transferring E-R or OO *concepts* to RDF. To me, the key point 
> is this: "Furthurmore,[sic] the set of slots of an object is not 
> defined when the class of an object is defined." The role of classes 
> in RDF is very different from the role of classes in E-R and OO. That 
> you CAN transform an RDBMS to RDF does not mean that the same 
> semantics apply. Caution should be applied, and some adjustments may 
> need to be made.
>
>
> Karen also said “FRBR has an OWL vocabulary called ‘FRBRer’ that has a 
> whole host of problems (not the least of which is a fairly deep 
> misunderstanding of OWL).” I am sure the FRBR Review Group would like 
> to correct any problems, so it would be useful if you could elaborate 
> on what the problems are. Also, please let us know what is being 
> misunderstood about OWL.
>
>
> Gordon, I assumed we had covered this at the DCMI2013 meeting in 
> Lisbon during the session on application profiles, where it was made 
> explicit that OWL is not a data validation language, which is why 
> there is an interest in application profiles that DO provide 
> constraints. The concept of "constraints" in OWL is not at all 
> analogous to the concept of constraints in languages like XSD, or in 
> E-R modeling. In fact, as the OWL documentation says:
>
> " OWL 2 is not a schema language for syntax conformance. Unlike XML, 
> OWL 2 does not provide elaborate means to prescribe how a document 
> should be structured syntactically. In particular, there is no way to 
> enforce that a certain piece of information (like the social security 
> number of a person) has to be syntactically present. " [2]
>
> In other words, 1) classes are not structures in RDF, although they 
> often perform a structural role in E-R and OO; and 2) OWL axioms do 
> not and cannot constrain the creation or validation of instance data: 
> OWL can only infer "truths" from data that exists. (Yes -- see below 
> -- ICV and others are using OWL with modified semantics to validate 
> data. Note: "modified semantics.")
>
> For the latter issue in that previous paragraph, the Open World 
> Assumption means that if owl:qualifiedCardinality on SSN is "1", and 
> no SSN is available, this is not an axiomatic inconsistency. In fact, 
> reasoners do not even note this fact because it is axiomatically 
> "true". (It's not terribly hard to test this in software like 
> Protege.) It merely means that the application will assume that there 
> is an SSN somewhere, just not here, now. If instead the search or 
> reasoner finds two SSNs, SSN1 and SSN2, it will conclude that
>
> SSN1 owl:sameAs SSN2
>
> That is quite different from how an E-R diagram or an RDBMS interprets 
> "one and only one." That is because OWL makes use of the non-unique 
> name assumption - that the same thing can have more than one name 
> (URI). Note that the same would be true in the use of 
> owl:qualifiedCardinality in FRBRer [0], where the "realizes" 
> relationship between FRBRer:expression and FRBRer:work has 
> owl:qualifiedCardinality "1". Thus, if a FRBRer:expression is a 
> FRBRer:realizationOf more than one FRBRer:work, those works will be 
> understood, axiomatically, as being the same work. Therefore, if, in a 
> particular environment (locally bounded or open on the web), one has 
> these two statements where owl:qualifiedCardinality for 
> FRBRer:realizationOf is "1"...
>
> ResourceB FRBRer:realizationOf ResourceC
> ResourceB FRBRer:realizationOf ResourceD
>
> Regardless of the human-meaningful values of ResourceC and ResourceD, 
> the inferred meaning is:
>
> ResourceC owl:sameAs ResourceD
>
> The identity of ResourceC could be intellectually "Moby Dick" and 
> Resource D "Little Women." But OWL reasoners will not find an 
> inconsistency between owl:qualifiedCardinality "1" and more than one 
> available resource.
>
> This is not what would result from and entity-relation statement of 
> "one and only one," and it is quite different from how one might use 
> cardinality in a *prescriptive* language, like XSD, or in OOP. It does 
> not conform, AFAIK, to the E-R analysis in FRBR. Nothing about OWL 
> constrains instance data to conform to what has been defined in OWL, 
> and OWL reasoners do not return "error messages" for some situations 
> that would trigger such messages in other languages. At the same time, 
> some inconsistencies, such as properties that violate disjointness 
> axioms, can result in the inability of the reasoner to operate at all 
> on the data. (This depends on the actions programmed into the reasoner.)
>
> OWL allows inferences on existing data, within the Open World 
> Assumption and Non-Unique Name assumption. (I wish that OWL 
> "constraints" had instead been named "axioms" because that is what 
> they are.) It is for this reason that RDF validation languages, like 
> SPIN [3], ICV [4], Shape Expression [5], and others are being 
> investigated in W3C -- because nearly everyone has a need for 
> validation, and OWL does not provide that.
>
> How this all relates to FRBRer, RDA and BIBFRAME is quite complex, but 
> hopefully there will be an article out on this topic before the end of 
> the year. The upshot is that moving from E-R and OO into RDF requires 
> some adjustments, both in thinking and modeling. It is also a good 
> idea to create tests that challenge our "previous software model" 
> assumptions.
>
> kc
> [0] http://metadataregistry.org/schema/show/id/5.rdf
> [1] http://www.w3.org/DesignIssues/RDB-RDF.html
> [2] http://www.w3.org/TR/2012/REC-owl2-primer-20121211
> [3] http://spinrdf.org
> [4] http://clarkparsia.com/pellet/icv
> [5] http://www.w3.org/2013/ShEx/Primer.html
>
>
>
> Cheers
>
> Gordon
>
> [1] http://www.w3.org/2001/sw/rdb2rdf/
>
> *From:*Bibliographic Framework Transition Initiative Forum 
> [mailto:[log in to unmask]] *On Behalf Of *Karen Coyle
> *Sent:* 26 July 2014 02:10
> *To:* [log in to unmask] <mailto:[log in to unmask]>
> *Subject:* Re: [BIBFRAME] BF vocabulary and RDA
>
> On 7/25/14, 4:45 PM, Robert Sanderson wrote:
>
>     While we're piling on...
>
>     On Fri, Jul 25, 2014 at 4:38 PM, Philip Evan Schreur
>     <[log in to unmask] <mailto:[log in to unmask]>> wrote:
>
>      Structure and data needs come first. Once that's settled, we look
>     to see how RDA can be expressed in that structure.
>
>     This is exactly it.  Bibframe should support RDA, not be
>     constrained by it.  Additional constraints can be layered on top,
>     for example via profiles.
>
>
> And RDA could be one of those profiles. But *something* has to be the 
> basis for the underlying data model. I believe that's what FRBR was 
> trying to be, but unfortunately, FRBR was designed around relational 
> database concepts and does not fit well into the RDF world. BIBFRAME 
> has devised its own model, although I'd like to see more discussion of 
> what that model is trying to represent. (Remember that many people are 
> not happy at how BF item data is modeled, and the definition of BF 
> annotation is still quite unclear.)
>
> RDA has its own RDF vocabulary [1] and may soon have a data creation 
> platform (at least a beta). (Note that RDA has 1676 properties (!).) 
> FRBR has an OWL vocabulary called "FRBRer" that has a whole host of 
> problems (not the least of which is a fairly deep misunderstanding of 
> OWL). [2] We have no dearth of RDF vocabularies (there's even one for 
> ISBD), but it's still not clear to me what direction we are going in 
> or what are the principles guiding the development of BIBFRAME. Not 
> that I would want to turn BIBFRAME development over to the catechism 
> that guides IFLA, but, really, what is it that we are doing?
>
> kc
> [1] http://rdaregistry.info/
> [2] http://iflastandards.info/ns/fr/frbr/frbrer/
>
>
>
> Rob
>
>
>
>
> -- 
> Karen Coyle
> [log in to unmask]  <mailto:[log in to unmask]>  http://kcoyle.net
> m: 1-510-435-8234
> skype: kcoylenet
>
>
>
> -- 
> Karen Coyle
> [log in to unmask]  <mailto:[log in to unmask]>  http://kcoyle.net
> m: 1-510-435-8234
> skype: kcoylenet

-- 
Karen Coyle
[log in to unmask] http://kcoyle.net
m: 1-510-435-8234
skype: kcoylenet