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Re: Defaults, Prototypes, Individuals in OWL - was: Re: FRBR and classes ('frbr:Works in the age of mechanical reproduction'...)

From: Karen Coyle <kcoyle@kcoyle.net>
Date: Fri, 18 Mar 2011 07:43:18 -0700
Message-ID: <20110318074318.141620kuz8gygeiu@kcoyle.net>
To: Antoine Isaac <aisaac@few.vu.nl>
Cc: Martin Hepp <martin.hepp@ebusiness-unibw.org>, public-lld@w3.org, Dan Brickley <danbri@danbri.org>, goodrelations <goodrelations@ebusiness-unibw.org>
I think this becomes possible with FRBR when a class is created either  
for Group 1 as a whole, with WEMI being subclasses of that class  
(frbrCore and FRBRoo both take this approach), and/or for the three  
FRBR groups as a whole. This was the essence of a lengthy (and  
non-recoverable) thread on the FRBR discussion list, with the parties  
breaking down into these "thought sets":

- FRBR needs a "super-class" so that relationships can be made to  
non-FRBR-ized bibliographic descriptions
- no super-class is needed because you can link to the  
frbr:manifestation (which then in turn links to Expression and Work)
- no super-class is needed because the Work represents the whole


Quoting Antoine Isaac <aisaac@few.vu.nl>:

> Hi Dan,
> Interesting stuff indeed :-) I wonder however whether the issue can  
> be sorted out in generality. Some randomly ordered two cents:
> - you need some "realization/reproduction" links between an abstract  
> FRBR resource and a less ghostly one, or between a design and  
> (re)productions of it. FRBR is not the only one facing that  
> requirement, models like DOLCE (the Information Objects part) or  
> CIDOC-CRM feature a comparable pattern. CRM is for museums, but art  
> that is exposed in musea now can be obtained via mechanization, or  
> subject to it for many purposes. One other important application  
> area for CRM, archeology, is of course full of "realizations" of a  
> more abstract design (think of coins). In fact if you want to bridge  
> to FRBR, you might be interested in FRBRoo, as model trying to  
> re-conciliate FRBR and CRM...
> - you need an operation that allows you to treat the more concrete  
> resources (in the above "realization" relationship) as the most  
> abstract resources in another realization relationship. OWL2 punning  
> is a solution for this, you may also think of foaf:focus as it  
> allows to associate an individual (concept) to anything more  
> concrete, which could be an OWL class. And in fact it's funny that  
> Martin got involved in this via the GoodRelations stuff, because a  
> couple of years ago he has also worked on a mechanism to bridge SKOS  
> concept schemes with "normal" ontologies, which seems to me quite  
> related.
> - once you have the patterns sketched above, you can apply them to  
> any number of "realization" levels. In the case of the library  
> domain as captured by FRBR it's 4, but in other domain as you hint  
> it, it could be less. It could be more as well. Very probably it  
> would depend on the application: here we bridge to the huge  
> discussion on the LLD list, where people were objecting that they  
> did not have the data to fully instantiate all the FRBR levels.  
> While in some case this lack is not intended, in other cases it  
> could be a fully conscious choice, based on the observation that  
> full compliance to the 4 levels would be impossible to reach for  
> data producers and/or useless for the data consumer or end user.
> - the prototype issue applies as soon as you have one level of  
> "realization" or instantiation, starting from the  
> "business-as-usual" class-instance modeling as in all simple OWL  
> ontologies. So I'm not sure it should be treated in strong relation  
> with the FRBR-like many-levels. As Martin's changing the thread  
> subject suggests it, I believe you could have split your impressive  
> post in 2 parts :-)
> Cheers,
> Antoine
>> Hi Dan,
>> Thanks for the interesting points, which I found only by accident. Just FYI:
>> Both http://www.productontology.org and GoodRelations  
>> (http://purl.org/goodrelations) try to cater for the need of  
>> modeling classes, individuals, and prototypes in an OWL DL world.
>> This happens by using
>> a) three subclasses of gr:ProductOrService:
>> - one for actual, identifiable individuals  
>> (gr:ActualProductOrServiceInstance)
>> - one for bags of anonymous individuals  
>> (gr:ProductOrServicesSomeInstancesPlaceholder)
>> - one for prototypes that define default attributes of individuals  
>> (gr:ProductOrServiceModel)
>> b) a link between the prototypes and individuals (gr:hasMakeAndModel)
>> So you can use common abstractions (e.g. pto:Laser_printer) for all  
>> of them while being able to keep them apart when needed by using  
>> the intersection of one of the three classes with the respective  
>> generic abstraction:
>> foo:MyLaserPrinter a pto:Laser_printer, gr:ActualProductOrServiceInstance ;
>> 	gr:serialNumber "123445X233"^^xsd:string .
>> foo:ProtypeForALaserprinter a pto:Laser_printer, gr:ProductOrServiceModel ;
>> 	color "black" .
>> Now, if we know that foo:ProtypeForALaserprinter is the prototype  
>> for foo:MyLaserPrinter via
>> foo:MyLaserPrinter gr:hasMakeAndModel foo:ProtypeForALaserprinter .
>> we can infer that it will have the color "black", unless we have  
>> information about the specific color of foo:MyLaserPrinter.
>> The actual reasoning for the defaults is beyond OWL DL, but can be  
>> well modeled e.g. in SPARQL CONSTRUCT rules:
>> (from  
>> http://www.ebusiness-unibw.org/wiki/GoodRelationsOptionalAxiomsAndLinks#Product_Models):
>> # Products inherit all product features from their product models  
>> unless they are defined for the products individually
>> CONSTRUCT {?product ?property ?valueModel.}
>> {
>>  {
>>    {?product a gr:ActualProductOrServiceInstance.}
>>    UNION
>>    {?product a gr:ProductOrServicesSomeInstancesPlaceholder.}
>>  }
>>    ?model a gr:ProductOrServiceModel.
>>    ?product gr:hasMakeAndModel ?model.
>>    ?model ?property ?valueModel.
>>  {
>>    {?property rdfs:subPropertyOf gr:qualitativeProductOrServiceProperty.}
>>    UNION
>>    {?property rdfs:subPropertyOf gr:quantitativeProductOrServiceProperty.}
>>    UNION
>>    {?property rdfs:subPropertyOf gr:datatypeProductOrServiceProperty.}
>>  }
>>  OPTIONAL {?product ?property ?valueProduct.}
>>  FILTER (!bound(?valueProduct))
>> }
>> So if foo:MyLaserPrinter does not have a gr:color property, the  
>> rule will add
>> foo:MyLaserPrinter gr:color "black" .
>> Otherwise, it will preserve the local value.
>> Quite clearly, an RDF dataspace can only do this once the set of  
>> relevant triples is defined; no true OWA.
>> While this was initially designed for the pretty narrow case of  
>> commodities and their datasheets, it can also be used for other  
>> pairs of individuals and prototypes, e.g. a composition and its  
>> performance (think of the duration of a piece of piano music).  
>> Also, the common abstraction for both may differ (e.g. the  
>> prototype could be a foo:Oil_painting and the individual a  
>> foo:Picture) or be pretty broad (e.g. foo:DVD).
>> Martin
>> (thinking-out-loud alert)
>> So this is a conversation that resurfaces over the years in various
>> ways. My latest prompt being a combination of (i) seeing
>> http://www.productontology.org/
>>  which declares OWL DL classes (ie.
>> classes of thing, aka types...) for commonly named products, using
>> Wikipedia data. The product ontology site uses OWL to describe classes
>> of largely mass-produced thing:
>> "This service provides GoodRelations-compatible OWL DL class
>> definitions for ca. 300,000 types of product or services that have an
>> entry in the English Wikipedia, e.g.
>> http://www.productontology.org/doc/Apple
>> http://www.productontology.org/doc/Laser_printer
>> http://www.productontology.org/doc/Manure_spreader
>> http://www.productontology.org/doc/Racing_bicycle
>> http://www.productontology.org/doc/Soldering_iron
>> http://www.productontology.org/doc/Sweet_potato
>> Back at DC-2008 in Berlin someone (maybe Karen Coyle or Diane Hillman)
>> mentioned that a difference between libraries and museums is that the
>> works collected by the former are mass produced.
>> I think we can go some way towards webbifying FRBR by pondering that
>> observation. I spent monday and tuesday with VU.nl colleagues visiting
>> the Amsterdam Museum and then the Fab Lab at
>> http://fablab.waag.org/
>> which showed some possibilities for taking museum artifacts and
>> replicating lossy copies of them (with 3d printers and other
>> mechanical reproduction techniques). We could even fabricate moulds
>> derrived from artifacts that allow others to create new derrived
>> instances (or their own moulds). Each generation derriving
>> characteristics from the previous, and adding in its own flaws and
>> innovations.
>> Looking at the Product Ontology examples above, they work better at
>> describing mechanically reproduced, near-identical artifacts -
>> Laser_printer, Soldering_Iron than with the natural kinds of thing -
>> apple, potato etc. Both apple and sweet potato are halfway to being
>> mass nouns --- you might often have need to describe 'some' apple or
>> sweet-potato, rather than 'a' sweet potato, although of course you can
>> have a specific apple or potato in-hand. Mass production brings with
>> it the prospect of thousands of *near*-identical instances of some
>> type, as well as associating those with codes and lately URLs that
>> link us back to information about the recipe or ingredients list for
>> those types of thing. For complex modern mass produced items, if you
>> know what kind of item it is, you know a huge amount about that thing
>> - whether it is a book or a printer or a soldering iron.
>> If we forget the library and cultural heritage scene for now, and
>> think just about these product types: I have here in my room a
>> specific laser printer. It is an HP Laser Smart C4270. Let's say it
>> was bought in Leiden, Netherlands and has an owner (this household).
>> It has specific characteristics local to this copy, as well as
>> stereotypical characteristics that it shares with all other "HP Laser
>> Smart C4270s".
>> FRBR isn't designed to describe that kind of situation (although the
>> parallels should be clear). But RDF and OWL do try to address that
>> general case: RDF/RDFS/OWL is very much in the business of drawing
>> such class-instance distinctions. OWL also goes some basic way towards
>> providing information-machinery for stating generalisations about all
>> the members of some class of thing. However OWL itself avoids certain
>> complex topics that are relatively hard to avoid for us: it does not
>> directly give us a way of saying '"typically". It does not give us a
>> way of distinguishing intrinsic versus accidental properties. The
>> latter saved W3C from retreading thousands of years of philosophical
>> debate. The former is perhaps a medium-sized nuisance. Regardless:
>> We can think of the class of things in the world that are *printers*.
>> We can name that class with a URI and publish a description there.
>> We can think of the class of things in the world that are *laser
>> printers*. We can name that class with a URI and publish a description
>> there.
>> We can think of the class of things in the world that are *HP laser
>> printers*. We can name that class with a URI and publish a description
>> there.
>> We can think of the class of things in the world that are *HP Laser
>> Smart C4270 printers*. We can name that class with a URI and publish a
>> description there.
>> We can associate any thing in the world with one of more of these
>> classes; in RDF by asserting an rdf:type relationship to the class. We
>> can use properties associated with the class to describe the
>> individual thing 'by hand', or we can draw factual conclusions about
>> properties of some individual from general knowledge that makes claims
>> about all members of a class.
>> We can go deeper, towards query-like classes, and name the sub-class
>> of HPLaserSmartC4270-Printer that corresponds to such printers bought
>> in Leiden; or owned by me. Or that have a damaged scanner lid and
>> which still serve adequately as a printer. Or which belong to the
>> subclass manufactured in the UK and that shipped with a UK-compatible
>> power cable.
>> OWL doesn't impose any appropriate level of detail on us, it just
>> provides descriptive primitives that let us talk in terms of [broadly]
>> sets of things, the properties that characterise those sets, and the
>> subset / superset relations between those sets. (We say class instead
>> of set, and leave that distinction aside for now.)
>> Computerised ontology languages like OWL are obsessed with this
>> class-vs-instance distinction, and in modern mass produced life, the
>> distinction is all around us, as are near-identical, mechanically
>> reproduced copies of products - regardless of whether the product was
>> designed to inform, educate, entertain, or remove unsightly nasal
>> hair.
>> Our FRBR-inspired conversations here are outshadowed by the need to
>> make equivalent distinctions in other aspects of everyday life. From
>> tracking down a replacement cable or scanner lid for my printer, to
>> finding the nearest open shop that will sell me a certain kind of
>> soldering iron on a sunday, or a certain DVD of a certain film, the
>> desire to organize information in a way that mirrors the patterns of
>> similarity amongst mass produced items is a modern universal.
>>> From
>> http://www.marxists.org/reference/subject/philosophy/works/ge/benjamin.htm
>> http://en.wikipedia.org/wiki/The_Work_of_Art_in_the_Age_of_Mechanical_Reproduction
>> and unfairly out of context,
>> "In principle a work of art has always been reproducible. Man-made
>> artifacts could always be imitated by men. Replicas were made by
>> pupils in practice of their craft, by masters for diffusing their
>> works, and, finally, by third parties in the pursuit of gain.
>> Mechanical reproduction of a work of art, however, represents
>> something new." [...] "With the woodcut graphic art became
>> mechanically reproducible for the first time, long before script
>> became reproducible by print. The enormous changes which printing, the
>> mechanical reproduction of writing, has brought about in literature
>> are a familiar story. However, within the phenomenon which we are here
>> examining from the perspective of world history, print is merely a
>> special, though particularly important, case."
>> All I'm suggesting here is that we follow this advice from Walter
>> Benjamin in 1936 and indulge ourselves in the idea that modeling
>> bibliographic mass production is merely a special (and important)
>> case.
>> FRBR's "items" are the most concrete, tangible entities in the FRBR
>> universe. In the physical realm they are things you might hold in your
>> hand, put in a box, find at some location. The idea extended to the
>> digital realm is naturally more ephemeral but we do at least have
>> correspondingly objective characterstics that ground digital objects
>> in clear ways: notions such as sizeInBytes, cryptographic hashes
>> (sha1sum, md5) can be used to talk precisely about specific sequences
>> of 'Zeros' and 'Ones'.
>> Looking up the FRBR hierarchy at the more general notions of
>> "Manifestation", "Expression" and "Work", these are FRBR's particular
>> story for organizing our millions of items into sensible groups.
>> FRBR's "work" notion is described textually as a “distinct
>> intellectual or artistic creation.”... a kind of ghostly but specific
>> entity, a kind of social fiction that acts as a descriptive (and
>> sometimes legal) hub for organizing clusters of related items.
>> "Expression" brings that somewhat down to earth (“the specific
>> intellectual or artistic form that a work takes each time it is
>> ‘realized.’”), while "Manifestion" finally articulates it in terms
>> sets/classes rather than individual abstract entities: " “the physical
>> embodiment of an expression of a work. As an entity, manifestation
>> represents all the physical objects that bear the same
>> characteristics, in respect to both intellectual content and physical
>> form.”".
>> So the distinctions made in terms of these *4* notions are similar to
>> those baked into the core of RDF itself.... specific fairly concrete
>> things organized into groups (sets, classes). RDF only allows itself
>> 'rdf:type' and 'rdfs:subClassOf' relationships as a basis to describe
>> all this.
>> So if we go with this idea that "print is merely a special, though
>> particularly important, case" of mass produced work, and that is it
>> worth investigating RDF descriptive habits that address
>> characteristics of mass production regardless of whether we are
>> talking about bicycles, books, laser printers or farmyard equipment,
>> ... where does this leave us? where does it get us?
>> 1. We bring more clearly into scope some industrialised areas of
>> cultural 'content' -- music, tv, films;
>> http://musicontology.com/
>> http://www.bbc.co.uk/ontologies/programmes/2009-09-07.shtml
>>  ... areas
>> where FRBR is a close but not perfect fit, and class-based models
>> drift towards being 'FRBR-inspired' rather than 'FRBR-based'.
>> 2. We find OWL lacks certain conventions for distinguishing
>> stereotypical instances from flawed/accidental characteristics of
>> actual instances. For eg. a copy of a some book I have on my desk
>> might be missing a certain page, so its literal 'number of pages'
>> property couldn't be inferred from a common class shared with other
>> such manifestations of the same abstraction. Or the local adjustments
>> made here to my printer (I swapped the power cable, or repaired the
>> lid). There is a big literature in KR about defaults and overrides and
>> it's tricky to get right with open-world design of RDF/OWL/RDFS.
>> 3. Works, Manifestations and Expressions might all just be kinds of
>> classes; or annotations on classes. The class of *HP Laser Smart C4270
>> printers* of which I have one in this room; the class of *SQL and
>> Relational Theory books* of which I have one on my desk as I type. The
>> former is described at
>> http://h10025.www1.hp.com/ewfrf/wc/product?cc=us&lc=en&dlc=en&product=3300222
>> by its maker;  the latter at
>> http://oreilly.com/catalog/9780596523084
>> ... more general classes might be tagged 'work-class'; very precise
>> classes tagged 'manifestation-class'. But fundamentally we get a huge,
>> universal spectrum (from the class of 'every Thing', to the class of
>> 'No-thing') rather than forcing each into one of the FRBR 4.
>> In both these example cases, there are product codes and online
>> databases, and other people who own different instances of the same
>> kind of thing. In both cases there are related products (maybe an
>> ebook, maybe a successor printer design, or ink cartridge) where
>> information at the level of 'all products' is useful to the owners and
>> custodians of specific products.
>> 4. OWL 2.0's punning mechanism may be relevant. This is a trick in OWL
>> 2 that lets a single URI serve both as a class identifier (the class
>> of C4270printers) but also as an identifier at the instance level, eg.
>> something that might have other data attached like images or links to
>> product documentation.
>> 5. We would effectively be abandoning the attempt to fit the
>> bibliographic universe into 4 buckets, and allowing different parties
>> to name and describe classes at any level of generality, picked out by
>> the properties of the things in that class. I might care to name a
>> class for all books written by all former pupils of the school
>> described at
>> http://en.wikipedia.org/wiki/RGS_High_Wycombe
>>  --- this
>> class would include SQL and Relational Theory, via its author,
>> http://dbpedia.org/page/Christopher_J._Date
>>   .... or you might care to
>> create a class for products whose primary inventor was an immigrant.
>> By stepping back from the FRBR 4, we could get a more free-form
>> environment in which properties of all kinds of thing can be used to
>> define whatever classes are useful.
>> 6. What does this mean in terms of 'who defines what when' metadata
>> practice? If the abstract work "SQL and Relational Theory" by C.J.Date
>> is in some sense now an RDF class, what should the URI be? Who
>> publishes it and what practice should exist around the associated
>> online description? I don't know. Maybe authors, publishers and
>> libraries all have a role, ... maybe there are 3 or more
>> semi-competing URIs for that class, one from C.J.Date, one from the
>> publisher O'Reilly or one or more from a library perspective. Perhaps
>> one of these descriptive agencies ends up playing a hub role and
>> including links to further description of the class from the other
>> parties. Maybe practices vary between fields and types of product. I
>> really don't know. And the core RDF/OWL specs are not the kinds of
>> thing that will tell us what's best to do, btw.
>> 7. What kinds of thing are properly expressed at the class level? I
>> also don't know. We might find value in rethinking some properties to
>> more explicitly attach them to the stereotypical ideal member of some
>> class, as a way of admitting that not all instances will match the
>> ideal. Perhaps for eg. the idea that books have 'numPages' could be
>> defined to refer to the stereotypical ideal case, even while applied
>> at the instance level. So if I lose 5 pages from the copy of "SQL and
>> Relational Theory" on my desk, we still say it has 410 numbered pages.
>> Maybe we go through and think 'which properties does it even make
>> sense to mutate at the instance level?". For all the damage I could do
>> to my copy of that book, I'm not going to change its author or
>> subject, for example. So those would be readily expressed in terms of
>> OWL. The numPages could be expressed as an OWL generalisation about
>> all instances if we define that property to be the ideal number,
>> rather than having to track damaged pages etc. And some properties
>> such as geographic location or owner make sense only at the instance
>> level. A few of these (such as e.g. initialOwner) might be static
>> properties that never change their value; others vary from time to
>> time.
>> Ok this post is too long already. Another way of stating all this is
>> that it's an appeal to think more in terms of specific
>> somehow-concrete items, things. Artifacts in your hand, or computer
>> data files that might be checksummed. And that all abstractions above
>> those are means to an end, rather than ends in themselves. So we can
>> ask whether, instead of pondering the vague characteristics of ghostly
>> entities like 'works', 'expressions' and 'manifestations', whether
>> we're simply talking about the common characteristics of collections
>> of identifiable *items*. And if that is what we're doing, whether (a)
>> we can more explicitly share common descriptive practices with other
>> non-textual mass produced kinds of things (b) whether RDF/OWL might
>> have some built-in facilities that could be used more (ie. its notion
>> of class).
>> This all wouldn't abolish the WEMI distinctions, rather they would as
>> sketched above, show up as a kind of annotation on RDF classes. Some
>> classes might be work-ish classes; the class of all Hamlets. Others
>> might be manifestation-ish classes; the class of all paper-printed
>> first edition SQL and Relational Theory copies. But the core
>> organising idea is sets/classes rather than the ghostly upper entities
>> of FRBR. Aspects of those entities would also show up as concrete
>> documents; an artists first sketches of a later painting; CJ Date's
>> book contract with O'Reilly that gave us the later book. First, second
>> and final drafts; hp printer schematics, blueprints; architectural
>> drawings; bike designs; ingredient lists and working notes. But rather
>> than merge our knowledge about all those practical things into the
>> vaguer composite entities of FRBR we just itemise them and describe
>> them as plain old artifacts at the instance level - giving us
>> something like a catalogue of evidence left in the world that shadows
>> the creative process, rather than reifying the act of creation into
>> special 'things' that can be described but never touched, used, read
>> or consumed.
>> Hope this all makes some sense. Related discussion from Bradley Allen,
>> Karen and others:
>> http://bpa.tumblr.com/post/10814190/faceted-classification-and-frbr
>> http://www.mail-archive.com/rda-l@listserv.lac-bac.gc.ca/msg03837.html
>> http://www.mail-archive.com/rda-l@listserv.lac-bac.gc.ca/msg03848.html
>> http://bibwild.wordpress.com/2007/12/07/frbr-considered-as-set-relationships/
>> http://lists.w3.org/Archives/Public/public-owl-dev/2008JulSep/0110.html
>> http://lists.w3.org/Archives/Public/public-lld/2010Sep/0049.html
>> cheers,
>> Dan
>> ps. I tried to draw some of this out graphically:
>> http://www.flickr.com/photos/danbri/2891150205/
>>   ... story of a
>> t-shirt design as frbr-inspired classes
>> http://www.flickr.com/photos/danbri/2892286406/in/photostream/
>>  ...same
>> story as a timeline
>> Received on Thursday, 17 March 2011 11:45:15 GMT
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Karen Coyle
kcoyle@kcoyle.net http://kcoyle.net
ph: 1-510-540-7596
m: 1-510-435-8234
skype: kcoylenet
Received on Friday, 18 March 2011 14:43:59 GMT

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